scholarly journals Upper and lower bounds on the speed of a one-dimensional excited random walk

2019 ◽  
Vol 12 (1) ◽  
pp. 97-115
Author(s):  
Erin Madden ◽  
Brian Kidd ◽  
Owen Levin ◽  
Jonathon Peterson ◽  
Jacob Smith ◽  
...  
2020 ◽  
Vol 88 (3) ◽  
Author(s):  
Roberta Massabò

Abstract Upper and lower bounds for the parameters of one-dimensional theories used in the analysis of sandwich fracture specimens are derived by matching the energy release rate with two-dimensional elasticity solutions. The theory of a beam on an elastic foundation and modified beam theory are considered. Bounds are derived analytically for foundation modulus and crack length correction in single cantilever beam (SCB) sandwich specimens and verified using accurate finite element results and experimental data from the literature. Foundation modulus and crack length correction depend on the elastic mismatch between face sheets and core and are independent of the core thickness if this is above a limit value, which also depends on the elastic mismatch. The results in this paper clarify conflicting results in the literature, explain the approximate solutions, and highlight their limitations. The bounds of the model parameters can be applied directly to specimens satisfying specific geometrical/material ratios, which are given in the paper, or used to support and validate numerical calculations and define asymptotic limits.


2008 ◽  
Vol 22 (23) ◽  
pp. 2163-2175 ◽  
Author(s):  
MIKLÓS HORVÁTH

We consider three-dimensional inverse scattering with fixed energy for which the spherically symmetrical potential is nonvanishing only in a ball. We give exact upper and lower bounds for the phase shifts. We provide a variational formula for the Weyl–Titchmarsh m-function of the one-dimensional Schrödinger operator defined on the half-line.


2015 ◽  
Vol 11 (07) ◽  
pp. 2037-2054 ◽  
Author(s):  
Ryan Broderick ◽  
Dmitry Kleinbock

The set of badly approximable m × n matrices is known to have Hausdorff dimension mn. Each such matrix comes with its own approximation constant c, and one can ask for the dimension of the set of badly approximable matrices with approximation constant greater than or equal to some fixed c. In the one-dimensional case, a very precise answer to this question is known. In this note, we obtain upper and lower bounds in higher dimensions. The lower bounds are established via the technique of Schmidt games, while for the upper bound we use homogeneous dynamics methods, namely exponential mixing of flows on the space of lattices.


1999 ◽  
Author(s):  
Izhak Sheinman ◽  
Yeoshua Frostig

Abstract Equivalent one-dimensional constitutive models of composite laminated beams with shear deformation are derived from the classical laminate two-dimensional using first-order shear deformable theory. The present cylindrical bending constitutive models can be used — with much greater accuracy than their well known plane-strain and plane-stress counterparts — as upper and lower bounds, to one of which the behavior tends depending on the width-to-length ratio; this aspect was investigated and results are presented.


2014 ◽  
Vol 17 (01) ◽  
pp. 1450005 ◽  
Author(s):  
DILIP B. MADAN ◽  
WIM SCHOUTENS

Postulating additivity of bid and ask prices for claims comonotone with a long or short stock position, two pricing processes are identified from data on bid and ask prices for options. It is observed that there are two separate put call parity relations in place, with the ask price for call less bid prices for put delivering an ask price for the forward-stock. Likewise the ask for puts less the bid for calls identifies the bid for the forward-stock. Two processes are introduced to determine bid and ask prices for claims comonotone with a long or short position in the stock. For a claim comonotone with a long position one uses the so-called increasing process for the ask price and the so-called decreasing process for the bid price and vice versa for a claim comonotone with a short position. As candidates for the two processes one may employ any of the traditional one-dimensional Markov processes. We illustrate the theory by using a Sato process, a model known to produce a smile conforming fit over strike and maturity. The two processes are observed to have marginals related by first order stochastic dominance. The increasing process dominates the decreasing process in this sense. These two processes are also used to construct upper and lower bounds for bid and ask prices for claims not comonotone with a long or short stock position. The two processes and their properties are illustrated with data on bid and ask prices for options on the exchange traded fund, SPY, that is the Standard and Poors' Depository Receipt tracking the S&P 500 index.


2008 ◽  
Vol 5 (2) ◽  
pp. 187-211
Author(s):  
S. Blaise ◽  
E. Deleersnijder

Abstract. A new parameterisation of horizontal salinity advection for a one-dimensional water-column estuarine model, inspired by the first-order finite-difference upwind scheme, is presented. This parameterisation prevents stratification from growing indefinitely, a numerical artefact usually referred to as "runaway stratification". It is seen that, using this upwind-like parameterisation, the salinity must remain comprised between upper and lower bounds set a priori and that any initial over- or under-shooting is progressively eliminated. Simulations of idealised and realistic estuarine regimes indicate that the new parameterisation lead to results that are devoid of the runaway stratification artefact, as opposed to previously used models.


Ocean Science ◽  
2008 ◽  
Vol 4 (4) ◽  
pp. 239-246 ◽  
Author(s):  
S. Blaise ◽  
E. Deleersnijder

Abstract. A new parameterisation of horizontal density gradient for a one-dimensional water column estuarine model, inspired by the first-order finite-difference upwind scheme, is presented. This parameterisation prevents stratification from growing indefinitely, a deficiency usually referred to as "runaway stratification". It is seen that, using this upwind-like parameterisation, the salinity must remain comprised between upper and lower bounds set a priori and that any initial over- or under-shooting is progressively eliminated. Simulations of idealised and realistic estuarine regimes indicate that the new parameterisation lead to results that are devoid of the runaway stratification phenomenon, as opposed to previously used models.


1971 ◽  
Vol 93 (4) ◽  
pp. 478-480 ◽  
Author(s):  
J. G. Wagner

Bounds are established on the errors associated with elastic-plastic strain wave measurements involving finite gage lengths. Attention is restricted to the case of one-dimensional wave propagation in a semi-infinite bar. A bi-linear model of the stress-strain behavior provides a means of calculating realistic upper and lower bounds on the relative error of amplitude measurements. Rise time errors are also discussed and illustrated.


Mathematics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 17 ◽  
Author(s):  
Abdollah Alhevaz ◽  
Maryam Baghipur ◽  
Hilal A. Ganie ◽  
Yilun Shang

The generalized distance matrix D α ( G ) of a connected graph G is defined as D α ( G ) = α T r ( G ) + ( 1 − α ) D ( G ) , where 0 ≤ α ≤ 1 , D ( G ) is the distance matrix and T r ( G ) is the diagonal matrix of the node transmissions. In this paper, we extend the concept of energy to the generalized distance matrix and define the generalized distance energy E D α ( G ) . Some new upper and lower bounds for the generalized distance energy E D α ( G ) of G are established based on parameters including the Wiener index W ( G ) and the transmission degrees. Extremal graphs attaining these bounds are identified. It is found that the complete graph has the minimum generalized distance energy among all connected graphs, while the minimum is attained by the star graph among trees of order n.


Sign in / Sign up

Export Citation Format

Share Document