Agency of Industrial Science and Technology

Other

Seiko Instruments Inc

Shogo Kiryu

Norio Chiba

Tetsuya Higuchi

Nobuhiro Shimizu

Masahiro Murakawa

Yuji Kasai

Toshio Adachi

Shiro Suzuki

Tsuneo Kikuchi

In an electronic circuit being provided with a plurality of circuit elements and performing a specified function, a plurality of specific circuit elements related to a circuit performing the specified function out of the plurality of circuit elements are composed of circuit elements changing their element parameters according to values indicated by control signals. The electronic circuit is provided with a plurality of holding circuits for holding a plurality of control signals to be given to the plurality of specific circuit elements. The values of the plurality of control signals which these holding circuits hold are changed by external or internal apparatuses according to a probabilistic searching technique (for example genetic algorithms or simulated annealing algorithms) so that the function of the electronic circuit satisfies designated specifications.

Electronic holding circuit and adjusting method thereof using a probabilistic searching technique

A magnetic field detecting circuit has a relaxation oscillator SQUID. An oscillator circuit includes a coil and a resistor connected together in series. The oscillator circuit produces an output signal having an oscillating frequency dependent on an applied DC bias current. A magnetic field input circuit is magnetically coupled with the coil of the oscillator circuit for applying a magnetic field. A Josephson device is connected in parallel with the oscillator circuit for converting the magnetic field to an electric signal for varying the oscillating frequency dependent on the magnetic field. The magnetic field is detected by detecting a variation of the oscillating frequency. The sensitivity of the magnetic field detecting circuit is improved by magnetically coupling an RF-SQUID with an input coil to form the magnetic field input circuit. To provide a multi-channel magnetic field detecting circuit, a plurality of oscillator circuits are connected in series with each other, and a respective Josephson device is connected in parallel with each corresponding oscillator circuit. A plurality of magnetic field input circuits are each magnetically coupled with the coil of a respective oscillator circuit, and a plurality of control lines are magnetically coupled with each respective Josephson device to vary the critical current of the Josephson device to thereby control the oscillation frequency of each oscillator circuit.

Magnetic field detecting circuit having a relaxation oscillator SQUID

Method of and apparatus for measuring a space distribution of spacings between point scatterers. An ultrasonic wave is applied to an ultrasonic scattering medium which is an aggregation of point scatterers. Ultrasonic waves, scattered from the medium, are converted into an electric signal. The shape of a power spectrum of the electric signal is determined. A fractal analysis is effected so as to determine a fractal dimension and self-similarity with respect to the power spectrum shape. A spatial distribution of a structural inhomogeneity of the scattering medium is measured in accordance with results of the fractal analysis.

Measuring spatial distribution of spacings between point scatterers

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Tsukuba, Japan

Shogo Kiryu