Abstract: A rail breakage detection device includes a first core part provided to a first cable connecting an electrical neutral point of an impedance bond that electrically connects a first rail and a second rail to the first rail, a second core part provided to a second cable connecting the electrical neutral point of the impedance bond to the second rail, a first coil wound around the first core part to generate a first electromotive force in accordance with a current variation occurring in the first cable, a second coil connected electrically to the first coil and wound around the second core part to generate a second electromotive force in accordance with a current variation occurring in the second cable, and a CPU to determine that the first or second rail is broken based on an electromotive force that is a sum of the first and second electromotive forces.

Abstract: A rail breakage detection device includes a first core part provided to a first cable connecting an electrical neutral point of an impedance bond that electrically connects a first rail and a second rail to the first rail, a second core part provided to a second cable connecting the electrical neutral point of the impedance bond to the second rail, a first coil wound around the first core part to generate a first electromotive force in accordance with a current variation occurring in the first cable, a second coil connected electrically to the first coil and wound around the second core part to generate a second electromotive force in accordance with a current variation occurring in the second cable, and a CPU to determine that the first or second rail is broken based on an electromotive force that is a sum of the first and second electromotive forces.

Abstract: A waveform estimation device includes: tracking filter processing units 11 and 12 that execute tracking filter processing on observation values using tracking filters having different drive noises; and a filter output selection unit 14 that selects a regular waveform component predicted by the tracking filter processing unit 11, in an irregular section, and selects a regular waveform component predicted by the tracking filter processing unit 12, in a regular section. A residual processing unit 16 calculates a residual between observation values extracted by an observation value extraction unit 1, and a regular waveform component selected by the filter output selection unit 14. An irregular waveform detection unit 17 determines whether the residual is an irregular waveform component.

Abstract: A waveform estimation device includes: tracking filter processing units 11 and 12 that execute tracking filter processing on observation values using tracking filters having different drive noises; and a filter output selection unit 14 that selects a regular waveform component predicted by the tracking filter processing unit 11, in an irregular section, and selects a regular waveform component predicted by the tracking filter processing unit 12, in a regular section. A residual processing unit 16 calculates a residual between observation values extracted by an observation value extraction unit 1, and a regular waveform component selected by the filter output selection unit 14. An irregular waveform detection unit 17 determines whether the residual is an irregular waveform component.

Abstract: A tsunami monitoring system includes a transmitting antenna configured to radiate a transmission signal to detect a tsunami as a radio wave toward a sea, and a receiving antenna configured to receive reflected waves reflected by the tsunami as a receiving signal. The tsunami monitoring system includes a signal generator circuit configured to generate the transmission signal having a predetermined frequency, a signal processor portion configured to generate a beat signal of a frequency difference between the transmission signal and the receiving signal, and a wave height estimator portion configured to divide a radio wave radiation region into a plurality of regions, calculate a flow velocity of a sea surface of the tsunami for each region on the basis of the beat signal, and estimate a wave height of the tsunami from a calculated flow velocity.

Abstract: A tsunami monitoring system includes a transmitting antenna configured to radiate a transmission signal to detect a tsunami as a radio wave toward a sea, and a receiving antenna configured to receive reflected waves reflected by the tsunami as a receiving signal. The tsunami monitoring system includes a signal generator circuit configured to generate the transmission signal having a predetermined frequency, a signal processor portion configured to generate a beat signal of a frequency difference between the transmission signal and the receiving signal, and a wave height estimator portion configured to divide a radio wave radiation region into a plurality of regions, calculate a flow velocity of a sea surface of the tsunami for each region on the basis of the beat signal, and estimate a wave height of the tsunami from a calculated flow velocity.

Abstract: A code converting apparatus is designed to estimate the incoming time and the like of a signal modulated by a spreading sequence composed of m elements in a set A having n kinds of symbols as elements accurately. A symbol sequence memory section 102 stores a converted sequence of symbols obtained by concatenating consecutive 2d symbols at the center of each sequence pattern pi composed of 4d elements in the set A. The converted sequence of symbols is structured so that d symbol immediately preceding the 2d symbols and d symbol immediately following the 2d symbols are identical to d symbol immediately preceding corresponding 2d symbols and d symbol immediately following the corresponding 2d symbols of a corresponding sequence pattern. A symbol sequence specifying section 103 specifies a matching sequence pattern for every consecutive 2d symbols in a symbol sequence obtained by assigning a symbol to the signal in a coding cycle of the spreading sequence.

Abstract: A multipath mitigation technology (MMT) can mitigate the influence of multipath when a received signal is composed of a single direct-path wave and a single multipath wave. However, in an actual environment, it is not always true that the number of multipath wave is only one. When a plurality of multipath waves is included in the received signal, the influence of multipath cannot be completely removed. On the contrary, when no multipath wave is included, an error occurs because a single direct-path wave is deemed as a single direct-path wave and a single multipath wave for estimation. In addition, difficulties arise in calculation when maximum likelihood estimation is performed targeting a time-domain signal. A positioning apparatus estimates parameters for a signal model by applying thereto the maximum likelihood estimation in the frequency domain, and estimates the signal model based on an information criterion, so that multipath errors are mitigated.

Abstract: An angular velocity/angular acceleration calculator of the crankshaft in an internal combustion engine includes a crank angle detection device, a crank angle correction device, and an angular velocity/angular acceleration calculation device. The crank angle detection device detects a crank angle in the internal combustion engine and a time at the crank angle. The crank angle correction device corrects the crank angle and the time thus detected to an equiangular crank angle and a time corresponding thereto. The angular velocity/angular acceleration calculation device calculates an angular velocity and an angular acceleration of the crankshaft by converting a function of the time with respect to the crank angle that are corrected by the crank angle correction device so as to be regarded as a periodic function, and utilizing the discrete Fourier transform of the converted function.

Abstract: A code converting apparatus is designed to estimate the incoming time and the like of a signal modulated by a spreading sequence composed of m elements in a set A having n kinds of symbols as elements accurately. A symbol sequence memory section 102 stores a converted sequence of symbols obtained by concatenating consecutive 2d symbols at the center of each sequence pattern pi composed of 4d elements in the set A. The converted sequence of symbols is structured so that d symbol immediately preceding the 2d symbols and d symbol immediately following the 2d symbols are identical to d symbol immediately preceding corresponding 2d symbols and d symbol immediately following the corresponding 2d symbols of a corresponding sequence pattern. A symbol sequence specifying section 103 specifies a matching sequence pattern for every consecutive 2d symbols in a symbol sequence obtained by assigning a symbol to the signal in a coding cycle of the spreading sequence.

Abstract: An angular velocity/angular acceleration calculator of the crankshaft in an internal combustion engine includes a crank angle detection device, a crank angle correction device, and an angular velocity/angular acceleration calculation device. The crank angle detection device detects a crank angle in the internal combustion engine and a time at the crank angle. The crank angle correction device corrects the crank angle and the time thus detected to an equiangular crank angle and a time corresponding thereto. The angular velocity/angular acceleration calculation device calculates an angular velocity and an angular acceleration of the crankshaft by converting a function of the time with respect to the crank angle that are corrected by the crank angle correction device so as to be regarded as a periodic function, and utilizing the discrete Fourier transform of the converted function.

Abstract: In the present invention, a conditional probability distribution function of received signal which is conditioned with a received signal amplitude (a), a pseudo range (p) and a navigation bit (bm) which are unknown parameters is acquired from a GPS signal sample S2 on the basis of a condition defined by a working hypothesis set in a working hypothesis setting part WH(i) and then the conditional probability distribution function (P(Rm|a, p, bm)) is marginalized with respect to the pseudo range (p) to acquire a marginal posterior probability distribution function (P(p|Rm, a)) in a step ST11. Finally acquired is a pseudo range dependent function in proportion to the marginal posterior probability distribution function (P(p|Rm, a)). Then, in a step ST12, a value of pseudo range (p) which gives the maximum value of pseudo range dependent function is determined as an estimated pseudo range.

Abstract: In the present invention, a conditional probability distribution function of received signal which is conditioned with a received signal amplitude (a), a pseudo range (p) and a navigation bit (bm) which are unknown parameters is acquired from a GPS signal sample S2 on the basis of a condition defined by a working hypothesis set in a working hypothesis setting part WH(i) and then the conditional probability distribution function (P(Rm|a, p, bm)) is marginalized with respect to the pseudo range (p) to acquire a marginal posterior probability distribution function (P(p|Rm, a)) in a step ST11. Finally acquired is a pseudo range dependent function in proportion to the marginal posterior probability distribution function (P(p|Rm, a)). Then, in a step ST12, a value of pseudo range (p) which gives the maximum value of pseudo range dependent function is determined as an estimated pseudo range.