다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

A survey for the quadratic assignment problem

Neuromorphic sensory systems.

We review the theory, fabrication, and implementation of the Josephson bifurcation amplifier (JBA). At the core of the JBA is a nonlinear oscillator based on a reactively shunted Josephson junction. A weak input signal to the amplifier couples to the junction critical current I(0) and results in a dispersive shift in the resonator plasma frequency omega(p). This shift is enhanced by biasing the junction with a sufficiently strong microwave current I(rf) to access the nonlinear regime where omega(p) varies with I(rf). For a drive frequency omega(d) such that Omega=2Q(1-omega(d)/omega(p))>3, the oscillator enters the bistable regime where two nondissipative dynamical states O(L) and O(H), which differ in amplitude and phase, can exist. The sharp I(0) dependent transition from O(L) to O(H) forms the basis for a sensitive digital threshold amplifier. In the vicinity of the bistable regime (Omega<3), analog amplification of continuous signals is also possible. We present experimental data characterizing amplifier performance and discuss two specific applications--the readout of superconducting qubits (digital mode) and dispersive microwave magnetometry (analog mode).

Invited Review Article: The Josephson bifurcation amplifier

Data based identification and prediction of nonlinear and complex dynamical systems

In two-dimensional parameter spaces, nonlinear systems producing solutions of a fixed periodicity form islands of a characteristic shape, called "shrimp"-shaped domains (SSDs). In simulations of electronic circuits, SSDs of different periodicities were recently found to be connected along spirals. By means of a hardware realization of the simulations, we provide a first direct proof of the real-world existence of this phenomenon. An improved description establishes a close experiment-simulation correspondence, and a simplified circuit family demonstrates the homoclinic saddle-focus origin of the phenomenon.

Real-world existence and origins of the spiral organization of shrimp-shaped domains.

Systems close to bifurcations can be used as small-signal amplifiers. Biophysical measurements suggest that the active amplifiers present in the mammalian cochlea are systems close to a Hopf bifurcation. The pure tone and transient signal output of our electronic hearing sensor based on this observation provides output that is fully compatible with the electrophysiological data from the mammalian cochlea. In particular, it reproduces all salient nonlinear effects displayed by the cochlea.

/pdf/analog-electronic-cochlea-with-mammalian-hearing-2g692784nq.pdf

Analog electronic cochlea with mammalian hearing characteristics

Some methods using artificial neural network were proposed for solving to the Two-Spiral Problem (TSP). TSP is a problem which classifies two spirals drawn on the plane, and it is famous as the high nonlinear problem. In this paper, we propose a chaos glial network which connected to Multi-Layer Perceptron (MLP). The chaos glial network is inspired by astrocyte which is glial cell in the brain. By computer simulations for solving TSP, we confirmed that the proposed chaos glial network connected to MLP gains better performance than the conventional MLP.

/pdf/chaos-glial-network-connected-to-multi-layer-perceptron-for-37gzeadnmk.pdf

Chaos glial network connected to Multi-Layer Perceptron for Solving Two-Spiral Problem

In this paper, performance of chaos and burst noises injected to the Hopfield Neural Network for quadratic assignment problems is investigated. For the evaluation of the noises, two methods to appreciate finding a lot of nearly optimal solutions are proposed. By computer simulations, it is confirmed that the burst noise generated by the Gilbert model with a laminar part and a burst part achieved the good performance as the intermittency chaos noise near the three-periodic window.

/pdf/performance-of-chaos-and-burst-noises-injected-to-the-3qfac3d2y4.pdf

Performance of chaos and burst noises injected to the hopfield nn for quadratic assignment problems

In this study, synchronization phenomena observed in van der Pol oscillators coupled by a time-varying resistor are investigated. We realize the time-varying resistor by switching a positive and a negative resistor periodically. By carrying out circuit experiments and computer calculations, interesting synchronization phenomena can be confirmed to be generated in this system. Namely, the synchronization states change according to the switching frequency of the time-varying resistor.

/pdf/synchronization-phenomena-in-van-der-pol-oscillators-coupled-fyduhu1o84.pdf

Yoko Uwate

Papers

Real-world existence and origins of the spiral organization of shrimp-shaped domains.

Analog electronic cochlea with mammalian hearing characteristics

Chaos glial network connected to Multi-Layer Perceptron for Solving Two-Spiral Problem

Performance of chaos and burst noises injected to the hopfield nn for quadratic assignment problems

Synchronization phenomena in van der pol oscillators coupled by a time-varying resistor