Fujitsu Corporation

The University of Tokyo

Motomu Takatsu

Satoshi Matsubara

Hiroaki Okamoto

Susumu Kawakami

Takao Sugawara

Masaru Sawada

Jumpei Koyama

Toshihiko Mori

Tatsuya Usuki

Noboru Yoneoka

Kazuya Takemoto

Yuichi Sato

Akihiro Yamazaki

Yasuhiko Arakawa

Sanroku Tsukamoto

Takayuki Shibasaki

Yasuhiro Watanabe

Shinichi Hirose

Toshihiko Morita

Kenichi Imamura

Akihiko Ohwada

Kazuhito Ichihara

Toshiyuki Miyazawa

A problem is inputted into an operation unit. A computation unit searches for a ground state of an Ising model. A management unit converts the problem inputted from the operation unit to the Ising model, inputs the Ising model produced by conversion and initial operating conditions into the computation unit, and has the computation unit search for the ground state using overall operating conditions produced by changing the initial operating conditions based on a result of the computation unit searching for the ground state using the initial operating conditions.

Optimization apparatus and control method for optimization apparatus using ising models

An information processing device includes: a memory; and a processor configured to: hold each of values of state variables included in an evaluation function representing energy; calculate the change value of the energy for each of state transitions, when a state transition occurs due to a change of any of the values of the state variables; control a temperature value representing temperature; select any of the state transitions, based on priority information set based on state transition information updated last time with respect to identification information for identifying each state transition, and transition acceptance information indicating transition acceptance determined based on the change value, and a generated thermal noise; and output a lowest energy state which is the values of the state variables when the energy to be updated based on the selected state transition becomes a lowest value.

Information processing device

An optimization device includes: search circuits, each configured to: hold values of state variables included in an evaluation function representing an energy value; calculate a change value of the energy value for each of state transitions which occurs in response to a change in one of the state variables; and determine stochastically whether to accept one of the state transitions according to a relative relationship between the change value of the energy value and thermal excitation energy, based on a set temperature value, the change value, and a random number value; and a controller configured to: acquire statistical information regarding a transition of a temperature value in each search circuit; determine a temperature value to be set in each search circuit based on the statistical information; set the temperature value for each search circuit; and exchange the temperature value or the values of the state variables between the search circuits.

Optimization device and control method of optimization device based on temperature statistical information

A random number generation device includes: a pseudo-random number generation circuit configured to generate a plurality of first pseudo-random numbers; and an orthogonal transformation circuit configured to generate a plurality of normal random numbers by performing orthogonal transformation on the plurality of first pseudo-random numbers, or by performing orthogonal transformation on the plurality of first pseudo-random numbers and a second pseudo-random number.

Random number generation device and random number generation method

An optimization device includes: a processor; and search circuits configured to determine energy values for combinations of two state variables of a state variables, based on weight values each indicating strength of connection between the two state variables, and values of the two state variables, determine values of the state variables, based on results of comparison between evaluation values obtained by adding a noise value corresponding to a temperature to each energy value, and a threshold value, and be set to be equal to each other in connection states between the state variables based on the weight values, the processor is configured to: determine an exchange count, based on a difference between a temperature set for a search circuit corresponding to the lowest energy value, and a minimum temperature; set a temperature for each search circuit; and exchange the set temperatures between the search circuits for the exchange count.

Optimization device and method of controlling optimization device utilizing a spin bit

An optimization device includes: a state hold circuit that holds values of state variables included in an evaluation function that represents energy; an objective function calculation circuit that calculates an energy change value in an objective function included in the evaluation function for each of state transitions when a state transition occurs in response to a change in any of the values of the state variables; a constraint term calculation circuit that calculates a constraint term evaluation value, which is an evaluation value of a constraint term included in the evaluation function, for each of the state transitions; a temperature control circuit that controls a temperature value that indicates a temperature; and a transition control circuit that determines stochastically whether to accept any of the state transitions based on the temperature value, a random number value, and a sum of the change value and the constraint term evaluation value.

Optimization device and control method of optimization device

A first evaluation function calculation unit and a second evaluation function calculation unit calculate a cost function term Eand a penalty function term Pin an evaluation function, respectively. A transition control unit stochastically determines whether to accept any of state transitions, based on a product of a ratio between an inverse temperature &#x3b2;and a penalty factor &#x3b1;and Pand E. An exchange control unit supplies &#x3b2;and &#x3b1;to each annealing unit, &#x3b2;and &#x3b1;having been set such that each annealing unit has a different ratio between &#x3b2;and &#x3b1;, receives Eand Pfrom each annealing unit, and exchanges &#x3b2;between first and second annealing units among the plurality of annealing units and &#x3b1;between the first and second annealing units, in accordance with a probability based on &#x3b2;, &#x3b1;, E, and Pof the first and second annealing units.

Optimization apparatus and control method thereof

When a transition control unit stochastically determines whether to accept one of a plurality of state transitions, using a temperature, an energy change, and a random number, depending on a relative relationship between the energy change and thermal excitation energy, the transition control unit adds an offset to the energy change, controls the offset so as to be larger at a local minimum, at which the energy is locally minimized, than at a solution at which the energy is not minimized, and resets the offset to zero when the energy change value is larger than a threshold.

Optimization apparatus and method of controlling the same

When stochastically deciding, based on a change in energy and a random number relating to thermal excitation, whether to accept any of a plurality of state transitions according to the relative relationship between the change in energy and thermal excitation energy, a transition control unit adds an offset to the change in energy, performs control so that the offset at a local minimum where energy is locally minimized is larger than an offset when the energy is not minimized, holds transition information (a transition number) indicating a previous state transition, and prohibits, based on a decoding result for the held transition information, a first state transition out of the present state transition candidates.

Optimization apparatus and method of controlling optimization apparatus

When a transition control section stochastically determines on the basis of a temperature, an energy change, and a random number whether to allow one of a plurality of state transitions according to a relative relationship between the energy change and a thermal excitation energy, the transition control section adds an offset to the energy change and exercises control so as to set the offset at a local minimum, at which an energy is locally minimized, to be larger than an offset at the time of the energy not being minimized.

Optimization apparatus and optimization apparatus control method

A stream encryption method encodes plaintext of N number of 1-bit input signal sequences into L (L is N or more) bits of encrypted text using N number of pseudo random sequences and uses only one pseudo random sequence used for the encryption to decode the single corresponding plaintext. This stream encryption method comprises using the N number of pseudo random sequences to divide a L-bit encryption symbol set averagely into two equal parts; selecting either of the two partial sets by a corresponding 1-bit plaintext sequence; and when there are one or more elements of the selected N number of partial sets forming common parts in the sets, using one of those as an encryption symbol.

Stream encryption method and encryption system

A single-photon generating device is configured to have a solid substrate including abase portion, and a pillar portion which is formed on the surface side of the base portion with a localized level existent in the vicinity of the tip of the base portion. The above pillar portion is formed to have a larger cross section on the base portion side than the cross section on the tip side, so that the light generated from the localized level is reflected on the surface, propagated inside the pillar portion, and output from the back face side of the base portion.

Single-photon generating device, single-photon detecting device, and optical quantum gate

A timing recovery unit detects a phase offset and a frequency offset from a head area of reproduction data and initially corrects them. The timing recovery unit stores data in which a head reproduction signal has been made to be discrete by a fixed clock into a buffer. A phase offset detector detects the phase offset from the data head area in parallel with the operation for writing the data into the buffer. At the same time, a frequency offset detector detects the frequency offset from the data head area in parallel with the operation for writing the data into the buffer. A correction value of the detected phase offset and a correction value of the detected frequency offset are initially set into a digital PLL. While the data is read out from the buffer, a frequency lead-in and a phase lead-in are executed in the head area.

Information recording and reproducing apparatus and method, and signal decoding circuit for performing timing recovery

A single-photon generator includes an exciton generation part including therein a quantum dot, an excitation part for generating an exciton in the exciton generator part, a recombination control part for controlling recombination timing of the exciton in the exciton generation part, and an optical window provided in the exciton generation part so as to pass a single photon formed as a result of recombination of the exciton, wherein the recombination control part causes, in the exciton generation part, recombination of the excitons at longer intervals than a recombination lifetime of a exciton molecule.

Single-photon generator and single-photon generating method

A linear filter feeds back an error signal generated using the output of an adaptive filter to a learning circuit. The learning circuit learns the coefficients of the adaptive filter using the error signal. The coefficients of the linear filter are determined depending on the generation method of a target signal for error minimization. In a signal interpolation type timing recovery digital filter, the coefficients of an inverse interpolation filter are determined in such a way as to minimize an error of a signal after interpolation.

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Shinjuku, Japan

Motomu Takatsu