New Classes of Random Tessellations Arising from Iterative Division of Cells

2010 ◽  
Vol 42 (1) ◽  
pp. 26-47 ◽  
Author(s):  
Richard Cowan

We present new ideas about the type of random tessellation which evolves through successive division of its cells. These ideas are developed in an intuitive way, with many pictures and only a modicum of mathematical formalism–so that the wide application of the ideas is clearly apparent to all readers. A vast number of new tessellation models, with known probability distribution for the volume of the typical cell, follow from the concepts in this paper. There are other interesting models for which results are not presented (or presented only through simulation methods), but these models have illustrative value. A large agenda of further research is opened up by the ideas in this paper.

2010 ◽  
Vol 42 (01) ◽  
pp. 26-47 ◽  
Author(s):  
Richard Cowan

We present new ideas about the type of random tessellation which evolves through successive division of its cells. These ideas are developed in an intuitive way, with many pictures and only a modicum of mathematical formalism–so that the wide application of the ideas is clearly apparent to all readers. A vast number of new tessellation models, with known probability distribution for the volume of the typical cell, follow from the concepts in this paper. There are other interesting models for which results are not presented (or presented only through simulation methods), but these models have illustrative value. A large agenda of further research is opened up by the ideas in this paper.


1996 ◽  
Vol 28 (02) ◽  
pp. 332
Author(s):  
Richard Cowan ◽  
Albert K. L. Tsang

This paper considers a structure, named a ‘random partition process’, which is a generalisation of a random tessellation. The cells, possibly multi-part and with holes, have a general topology summarised by the Euler characteristic. Vertices of all orders are allowed. Using the tools of ergodic theory, all of the formulae, from the traditional theory of random tessellations with convex cells, are generalised. Some motivating examples are given.


1996 ◽  
Vol 28 (02) ◽  
pp. 338-339 ◽  
Author(s):  
Roger E. Miles ◽  
Margaret S. Mackisack

It is well-known that Poisson lines in the plane, with orientation distribution Θ on [0, π), generate a (random) tessellation M 0 of (random) convex polygons whose characteristics (area, perimeter, etc.) conform, in an ergodic sense, to a certain class {D Θ} of distributions.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Agnieszka Blokus-Roszkowska ◽  
Leszek Smolarek

Maritime transport is of great importance as it is the basis of international trade. Shipping is a global industry and highly complex business. Further safety development at sea is determined by the growth of maritime traffic intensity. Therefore, new ideas and technologies are needed to optimize the sea transport system. In the paper, the cellular automaton model is suggested to describe traffic flow at grade roundabout and simple crossing. Not only the cell state but also neighborhood as well is defined for presented cellular automaton. The model, describing vessels motion, takes into account vessel’s type, speed and length, vessel’s behavior and maneuverability, lane status, and flow density. It provides the basis for simulation. Two types of traffic schemes, namely, roundabout and simple routes crossing, are considered. Some results of simulation, including ships safety prediction, illustrate possible applications for evaluation of maritime traffic organization. Final conclusion and remarks outline further work development.


1991 ◽  
Vol 06 (12) ◽  
pp. 2175-2187
Author(s):  
A.G. GROZIN

The usual simulation methods are inapplicable for a particle in a non-simply-connected space, because closed paths are divided into homotopy classes. The probability distribution over these classes is calculated analytically at low temperatures. A simulation algorithm is proposed.


2010 ◽  
Vol 29 (3) ◽  
pp. 143 ◽  
Author(s):  
Christoph Thäle ◽  
Viola Weiss

Homogeneous random tessellations in the 3-dimensional Euclidean space are considered that are stable under iteration – STIT tessellations. A classification of vertices, segments and flats is introduced and a couple of new metric and topological mean values for them and for the typical cell are calculated. They are illustrated by two examples, the isotropic and the cuboid case. Several extremum problems for these mean values are solved with the help of techniques from convex geometry by introducing an associated zonoid for STIT tessellations.


1992 ◽  
Vol 14 (14) ◽  
pp. 71
Author(s):  
Orimar Antônio Battistel

We present a discussion of some of the ideas and facts that led to the modern conception of the structure of matter in terms of basic constituents and fundamental interactions. We discuss the construction of the quark model in a historical context, stressing that the phenomenological knowledge of particle properties induced the mathematical formalism. The interaction between quarks is discussed in the framework of the color force based on the exchange of gluons. For the sake of completeness we mention briefly the microworld structure that emerged from these new ideas.


Quantum ◽  
2020 ◽  
Vol 4 ◽  
pp. 235 ◽  
Author(s):  
Yingkai Ouyang ◽  
David R. White ◽  
Earl T. Campbell

Simulation of quantum chemistry is expected to be a principal application of quantum computing. In quantum simulation, a complicated Hamiltonian describing the dynamics of a quantum system is decomposed into its constituent terms, where the effect of each term during time-evolution is individually computed. For many physical systems, the Hamiltonian has a large number of terms, constraining the scalability of established simulation methods. To address this limitation we introduce a new scheme that approximates the actual Hamiltonian with a sparser Hamiltonian containing fewer terms. By stochastically sparsifying weaker Hamiltonian terms, we benefit from a quadratic suppression of errors relative to deterministic approaches. Relying on optimality conditions from convex optimisation theory, we derive an appropriate probability distribution for the weaker Hamiltonian terms, and compare its error bounds with other probability ansatzes for some electronic structure Hamiltonians. Tuning the sparsity of our approximate Hamiltonians allows our scheme to interpolate between two recent random compilers: qDRIFT and randomized first order Trotter. Our scheme is thus an algorithm that combines the strengths of randomised Trotterisation with the efficiency of qDRIFT, and for intermediate gate budgets, outperforms both of these prior methods.


1996 ◽  
Vol 28 (2) ◽  
pp. 332-332
Author(s):  
Richard Cowan ◽  
Albert K. L. Tsang

This paper considers a structure, named a ‘random partition process’, which is a generalisation of a random tessellation. The cells, possibly multi-part and with holes, have a general topology summarised by the Euler characteristic. Vertices of all orders are allowed. Using the tools of ergodic theory, all of the formulae, from the traditional theory of random tessellations with convex cells, are generalised. Some motivating examples are given.


2018 ◽  
Author(s):  
Elizabeth Bonawitz ◽  
Stephanie Denison ◽  
Tom Griffiths ◽  
Alison Gopnik

Although probabilistic models of cognitive development have become increasingly prevalent, one challenge is to account for how children might cope with a potentially vast number of possible hypotheses. We propose that children might address this problem by ‘sampling’ hypotheses from a probability distribution. We discuss empirical results demonstrating signatures of sampling, which offer an explanation for the variability of children's responses. The sampling hypothesis provides an algorithmic account of how children might address computationally intractable problems and suggests a way to make sense of their ‘noisy’ behavior.


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