scholarly journals Fractal energy transport: Random walk simulations on long-range percolation clusters

1984 ◽  
Vol 31-32 ◽  
pp. 654-656 ◽  
Author(s):  
Panos Argyrakis ◽  
Raoul Kopelman
1985 ◽  
Vol 31 (9) ◽  
pp. 6008-6011 ◽  
Author(s):  
P. Argyrakis ◽  
R. Kopelman

Nature ◽  
2015 ◽  
Vol 523 (7559) ◽  
pp. 196-199 ◽  
Author(s):  
Andreas T. Haedler ◽  
Klaus Kreger ◽  
Abey Issac ◽  
Bernd Wittmann ◽  
Milan Kivala ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247133
Author(s):  
Jun Shimizu ◽  
Hiromi Kuwata ◽  
Kazuo Kuwata

Fractal dimensions and characteristic periodicities were evaluated in normal sentences, computer-generated word salads, and word salads from schizophrenia patients, in both Japanese and English, using the random walk patterns of vowels. In normal sentences, the walking curves were smooth with gentle undulations, whereas computer-generated word salads were rugged with mechanical repetitions, and word salads from patients with schizophrenia were unreasonably winding with meaningless repetitive patterns or even artistic cohesion. These tendencies were similar in both languages. Fractal dimensions between normal sentences and word salads of schizophrenia were significantly different in Japanese [1.19 ± 0.09 (n = 90) and 1.15 ± 0.08 (n = 45), respectively] and English [1.20 ± 0.08 (n = 91), and 1.16 ± 0.08 (n = 42)] (p < 0.05 for both). Differences in long-range (>10) periodicities between normal sentences and word salads from schizophrenia patients were predominantly observed at 25.6 (p < 0.01) in Japanese and 10.7 (p < 0.01) in English. The differences in fractal dimension and characteristic periodicities of relatively long-range (>10) presented here are sensitive to discriminate between schizophrenia and healthy mental state, and could be implemented in social robots to assess the mental state of people in care.


2020 ◽  
Vol 178 (3-4) ◽  
pp. 1173-1192 ◽  
Author(s):  
Jean Bertoin

Abstract A reinforcement algorithm introduced by Simon (Biometrika 42(3/4):425–440, 1955) produces a sequence of uniform random variables with long range memory as follows. At each step, with a fixed probability $$p\in (0,1)$$ p ∈ ( 0 , 1 ) , $${\hat{U}}_{n+1}$$ U ^ n + 1 is sampled uniformly from $${\hat{U}}_1, \ldots , {\hat{U}}_n$$ U ^ 1 , … , U ^ n , and with complementary probability $$1-p$$ 1 - p , $${\hat{U}}_{n+1}$$ U ^ n + 1 is a new independent uniform variable. The Glivenko–Cantelli theorem remains valid for the reinforced empirical measure, but not the Donsker theorem. Specifically, we show that the sequence of empirical processes converges in law to a Brownian bridge only up to a constant factor when $$p<1/2$$ p < 1 / 2 , and that a further rescaling is needed when $$p>1/2$$ p > 1 / 2 and the limit is then a bridge with exchangeable increments and discontinuous paths. This is related to earlier limit theorems for correlated Bernoulli processes, the so-called elephant random walk, and more generally step reinforced random walks.


Nanoscale ◽  
2019 ◽  
Vol 11 (44) ◽  
pp. 21196-21206 ◽  
Author(s):  
Dylan H. Arias ◽  
Dana B. Sulas-Kern ◽  
Stephanie M. Hart ◽  
Hyun Suk Kang ◽  
Ji Hao ◽  
...  

Exciton delocalization impacts complex interplay between rapid downhill exciton energy transfer and long-range energy transport through carbon nanotube networks.


NeuroImage ◽  
2016 ◽  
Vol 141 ◽  
pp. 442-451 ◽  
Author(s):  
F. von Wegner ◽  
E. Tagliazucchi ◽  
V. Brodbeck ◽  
H. Laufs

2018 ◽  
Vol 29 (01) ◽  
pp. 1850008 ◽  
Author(s):  
N. Posé ◽  
K. J. Schrenk ◽  
N. A. M. Araújo ◽  
H. J. Herrmann

Real landscapes exhibit long-range height–height correlations, which are quantified by the Hurst exponent [Formula: see text]. We give evidence that for negative [Formula: see text], in spite of the long-range nature of correlations, the statistics of the accessible perimeter of isoheight lines is compatible with Schramm–Loewner evolution curves and therefore can be mapped to random walks, their fractal dimension determining the diffusion constant. Analytic results are recovered for [Formula: see text] and [Formula: see text] and a conjecture is proposed for the values in between. By contrast, for positive [Formula: see text], we find that the random walk is not Markovian but strongly correlated in time. Theoretical and practical implications are discussed.


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