NOISE-INDUCED TRANSMISSION OF SIGNALS THROUGH A CHAIN OF LEVEL-CROSSING DETECTORS

2003 ◽  
Vol 03 (01) ◽  
pp. L11-L22 ◽  
Author(s):  
NOBUKO FUCHIKAMI ◽  
TOSHIFUMI SAKAGUCHI

We study noise-assisted propagation of periodic signals for one-dimensional arrays composed of one-way coupled level-crossing detectors (LCD). Analytical expressions are obtained for the signal decay length through chains and the signal decay time through rings, where noise is uncorrelated so that the signal transmission from a LCD to the neighboring one is Markovian. Recent numerical simulations for one-dimensional arrays of one-way coupled bistable oscillators are discussed in comparison to the present analytical results.

Author(s):  
Dominic Vella ◽  
Emmanuel du Pontavice ◽  
Cameron L. Hall ◽  
Alain Goriely

Spherical neodymium–iron–boron magnets are permanent magnets that can be assembled into a variety of structures owing to their high magnetic strength. A one-dimensional chain of these magnets responds to mechanical loadings in a manner reminiscent of an elastic rod. We investigate the macroscopic mechanical properties of assemblies of ferromagnetic spheres by considering chains, rings and chiral cylinders of magnets. Based on energy estimates and simple experiments, we introduce an effective magnetic bending stiffness for a chain of magnets and show that, used in conjunction with classic results for elastic rods, it provides excellent estimates for the buckling and vibration dynamics of magnetic chains. We then use this estimate to understand the dynamic self-assembly of a cylinder from an initially straight chain of magnets.


1998 ◽  
Vol 01 (04) ◽  
pp. 473-486 ◽  
Author(s):  
Roberto Baviera ◽  
Michele Pasquini ◽  
Maurizio Serva ◽  
Angelo Vulpiani

We consider a stochastic model of investment on an asset in a stock market for a prudent investor. she decides to buy permanent goods with a fraction α of the maximum amount of money owned in her life in order that her economic level never decreases. The optimal strategy is obtained by maximizing the exponential growth rate for a fixed α. We derive analytical expressions for the typical exponential growth rate of the capital and its fluctuations by solving an one-dimensional random walk with drift.


2014 ◽  
Vol 13 (04) ◽  
pp. 1430001 ◽  
Author(s):  
Jaume Masoliver

We review the level-crossing problem which includes the first-passage and escape problems as well as the theory of extreme values (the maximum, the minimum, the maximum absolute value and the range or span). We set the definitions and general results and apply them to one-dimensional diffusion processes with explicit results for the Brownian motion and the Ornstein–Uhlenbeck (OU) process.


2005 ◽  
Vol 94 (5) ◽  
pp. 3406-3416 ◽  
Author(s):  
Ofer Feinerman ◽  
Menahem Segal ◽  
Elisha Moses

Dissociated neurons were cultured on lines of various lengths covered with adhesive material to obtain an experimental model system of linear signal transmission. The neuronal connectivity in the linear culture is characterized, and it is demonstrated that local spiking activity is relayed by synaptic transmission along the line of neurons to develop into a large-scale population burst. Formally, this can be treated as a one-dimensional information channel. Directional propagation of both spontaneous and stimulated bursts along the line, imaged with the calcium indicator Fluo-4, revealed the existence of two different propagation velocities. Initially, a small number of neighboring neurons fire, leading to a slow, small and presumably asynchronous wave of activity. The signal then spontaneously develops to encompass much larger and further populations, and is characterized by fast propagation of high-amplitude activity, which is presumed to be synchronous. These results are well described by an existing theoretical framework for propagation based on an integrate-and-fire model.


2019 ◽  
Vol 34 (6) ◽  
pp. 339-351 ◽  
Author(s):  
Petr S. Kondratenko ◽  
Leonid V. Matveev ◽  
Alexander D. Vasiliev

Abstract A new method is developed to calculate characteristics of contaminant transport (including non-classical regimes) in statistically homogeneous sharply contrasting media. A transport integro-differential equation in the space-time representation is formulated on the basis of the model earlier proposed by one of the authors (L. M.). Analytical expressions for transport characteristics in limiting time intervals in the one-dimensional case are derived. An interpolation form is proposed for the integral kernel of the transport equation. On a basis of this expression, an algorithm is developed for numerical modelling the contaminant transport in statistically homogeneous sharply contrasting media. Trial numerical 1D calculations are performed based on this algorithm. Good agreement was found between the numerical simulation results and the asymptotic analytical expressions.


2019 ◽  
Vol 30 (14) ◽  
pp. 2147-2165 ◽  
Author(s):  
Alireza Ostadrahimi ◽  
Fathollah Taheri-Behrooz

In this article, an analytical solution is presented for twinning deformation effect of a prismatic shape memory alloy beam-column. To this end, a reduced one-dimensional Souza model is employed to study the bending stress of a pre-strained shape memory alloy beam-column at low temperatures. Analytical expressions for bending stress as well as polynomial approximations for deflection are obtained. Derived equations for bending problem are employed to analyze twinning deformation effect of shape memory alloy beam-columns with rectangular and circular cross sections. Furthermore, the distance of zero-stress fiber from the center line during loading is studied. The results of this work show good agreement when compared with experimental data and finite element results.


1996 ◽  
Vol 157 ◽  
pp. 372-374
Author(s):  
Mattias Wahde ◽  
Karl Johan Donner

AbstractA simple formula is derived for the force of dynamical friction acting on a satellite galaxy which is moving on a nearly circular orbit around its parent galaxy. Using this formula, estimates of the decay time are computed. The results are then compared with the corresponding results from numerical simulations, and are found to be in good agreement.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Lian he Li ◽  
Yue Zhao

Interaction of a screw dislocation with wedge-shaped cracks in one-dimensional hexagonal piezoelectric quasicrystals bimaterial is considered. The general solutions of the elastic and electric fields are derived by complex variable method. Then the analytical expressions for the phonon stresses, phason stresses, and electric displacements are given. The stresses and electric displacement intensity factors of the cracks are also calculated, as well as the force on dislocation. The effects of the coupling constants, the geometrical parameters of cracks, and the dislocation location on stresses intensity factors and image force are shown graphically. The distribution characteristics with regard to the phonon stresses, phason stresses, and electric displacements are discussed in detail. The solutions of several special cases are obtained as the results of the present conclusion.


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