Abstract: A flow rate control device includes a piezo valve having a metal diaphragm valve element that is opened and closed by a piezo actuator, a strain sensor for detecting a displacement amount of the piezo actuator, and a control circuit for receiving a detection signal of the strain sensor and controlling a drive voltage of the piezo actuator, wherein the control circuit is configured so as, by applying a positive drive voltage one or more times and then applying a negative drive voltage a plurality of times to the piezo actuator at a desired timing, to bring an amount of strain detected by the strain sensor close to zero when no drive voltage is applied to the piezo actuator.

Abstract: The flow controller according to the present invention includes: a control valve; a first flow passage provided on the downstream side of the control valve; a second flow passage; and an expansion chamber provided between the first flow passage and the second flow passage. The second flow passage is provided in a position that is not on the extension of the first flow passage.

Abstract: The flow controller according to the present invention includes: a control valve; a first flow passage provided on the downstream side of the control valve; a second flow passage; and an expansion chamber provided between the first flow passage and the second flow passage. The second flow passage is provided in a position that is not on the extension of the first flow passage.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: A method is provided for recurrently estimating a spectrum of noise at each signal observation interval from a sound signal which contains the noise and which is observed at each signal observation interval. In the method, there are acquired an envelope of a previous spectrum of the noise which has been previously estimated from the sound signal observed at a previous signal observation interval, and an envelope of a current spectrum of the sound signal which is observed at a current signal observation interval subsequent to the previous signal observation interval. Then, a value of correlation is computed between the envelop of the previous spectrum of the noise and the envelope of the current spectrum of the sound signal. A current spectrum of the noise contained in the sound signal observed at the current signal observation interval is estimated in accordance with the computed value of the correlation and based on the previous spectrum of the noise and the current spectrum of the sound signal.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: A tire air pressure monitoring system is provided that comprises a transmitting device, a receiving device, and a tire identification number registration device. The transmitting device is mounted on a wheel of a vehicle, and configured and arranged to wirelessly transmit a signal indicative of at least tire air pressure information of a tire coupled to the wheel and a tire identification number assigned to the wheel. The receiving device is mounted on the vehicle, and configured and arranged to receive the signal transmitted from the transmitting device. The tire identification number registration device is configured to estimate a position of the wheel with respect to the vehicle based on correlation information corresponding to an extent of a correlation between strength of the signal and a tire rotational angle of the wheel, and to register the tire identification number with the position of the wheel.

Abstract: Sound picked up by a microphone of a first sound field is reproduced by a speaker of a second sound field, and a sound picked up by a microphone of the second sound field is reproduced by the speaker of the first sound field. Sound pressure detection section detects a sound pressure of a sound present in the second (or first) sound field picked up by the microphone of the second (or first) sound field, other than a sound reproduced by the speaker of the first (or second) sound field. Other sound pressure detection section detects a sound pressure with which the sound picked up by the microphone of the second (or first) sound field and reproduced by the speaker of the first (or second) sound field is picked up by the microphone of the first (or second) sound field. Sound-pressure-difference detection section adjusts a gain of an automatic gain adjustment section in such a manner that the two detected sound pressures assume a predetermined relationship.

Abstract: A tire air pressure monitoring system is provided that comprises a transmitting device, a receiving device, and a tire identification number registration device. The transmitting device is mounted on a wheel of a vehicle, and configured and arranged to wirelessly transmit a signal indicative of at least tire air pressure information of a tire coupled to the wheel and a tire identification number assigned to the wheel. The receiving device is mounted on the vehicle, and configured and arranged to receive the signal transmitted from the transmitting device. The tire identification number registration device is configured to estimate a position of the wheel with respect to the vehicle based on correlation information corresponding to an extent of a correlation between strength of the signal and a tire rotational angle of the wheel, and to register the tire identification number with the position of the wheel.

Abstract: A method is provided for recurrently estimating a spectrum of noise at each signal observation interval from a sound signal which contains the noise and which is observed at each signal observation interval. In the method, there are acquired an envelope of a previous spectrum of the noise which has been previously estimated from the sound signal observed at a previous signal observation interval, and an envelope of a current spectrum of the sound signal which is observed at a current signal observation interval subsequent to the previous signal observation interval. Then, a value of correlation is computed between the envelop of the previous spectrum of the noise and the envelope of the current spectrum of the sound signal. A current spectrum of the noise contained in the sound signal observed at the current signal observation interval is estimated in accordance with the computed value of the correlation and based on the previous spectrum of the noise and the current spectrum of the sound signal.

Abstract: An apparatus is designed for processing a first audio signal at transmission and a second audio signal upon receipt so as to determine whether the second audio signal is provided under a double-talk state or a single-talk state. In the apparatus, a storage section stores the first audio signal. A convolution section convolutes the stored first audio signal with a variable coefficient to produce a reference signal. The variable coefficient is updated by an update addition value. A subtraction section subtracts the reference signal from the second audio signal to provide an error signal. A computation section computes the update addition value for the variable coefficient on the basis of the error signal and the first audio signal. A determination section determines whether the second audio signal is provided under the double-talk state or the single-talk state on the basis of the update addition value.

Abstract: Two signals, which are mutually correlated, are subjected to a principal component analysis and converted into two signals being put in an orthogonal relation, thereby generating two signals being non-correlated. Those two signals are reproduced by speakers, and the voice generated from the speakers are collected by microphones. The cross spectra of a signal as the result of subtracting an echo canceling signal from a voice collected by each microphone, and a voice before it is generated from the speaker, are obtained. Those cross spectra are ensemble-averaged for a predetermined period of time, and inverse Fourier transformed, thereby producing impulse response estimation errors of each filter. Impulse responses of those filters are updated so as to cancel those impulse response estimation errors.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: Two signals, which are mutually correlated, are subjected to a principal component analysis and converted into two signals being put in an orthogonal relation, thereby generating two signals being non-correlated. Those two signals are reproduced by speakers, and the voice generated from the speakers are collected by microphones. The cross spectra of a signal as the result of subtracting an echo canceling signal from a voice collected by each microphone, and a voice before it is generated from the speaker, are obtained. Those cross spectra are ensemble-averaged for a predetermined period of time, and inverse Fourier transformed, thereby producing impulse response estimation errors of each filter. Impulse responses of those filters are updated so as to cancel those impulse response estimation errors.

Abstract: Sound picked up by a microphone of a first sound field is reproduced by a speaker of a second sound field, and a sound picked up by a microphone of the second sound field is reproduced by the speaker of the first sound field. Sound pressure detection section detects a sound pressure of a sound present in the second (or first) sound field picked up by the microphone of the second (or first) sound field, other than a sound reproduced by the speaker of the first (or second) sound field. Other sound pressure detection section detects a sound pressure with which the sound picked up by the microphone of the second (or first) sound field and reproduced by the speaker of the first (or second) sound field is picked up by the microphone of the first (or second) sound field. Sound-pressure-difference detection section adjusts a gain of an automatic gain adjustment section in such a manner that the two detected sound pressures assume a predetermined relationship.

Abstract: An unreacted gas detector including a reactor unit for producing a target gas by way of reacting material gases in its reaction chamber, a sensor body connected to the reactor unit, a measurement space provided in the sensor body for allowing the target gas to flow, an unreacted gas sensor having a temperature measurement section covered by a catalyst layer and disposed inside the measurement space, and a target gas sensor with its temperature measurement section disposed in the sensor body. Any unreacted gas remaining in the target gas is reacted by the catalyst layer so that a resulted temperature change is detected by the unreacted gas sensor, and a target gas temperature is measured by target gas temperature sensor, thus finding a unreacted gas concentration from a temperature difference between the temperatures obtained by the unreacted gas sensor and the target gas temperature sensor.

Abstract: A reactor (2) for generating moisture in which the starting material gases are caused to undergo turbulence so as to increase the efficiency of the moisture-generating reaction.