Joshua Socolar

Journal Article Physical Review B · December 1, 2023 Tiling models can reveal unexpected ways in which local constraints give rise to exotic long-range spatial structure. The recently discovered hat monotile (and its mirror image) has been shown to be aperiodic [Smith, arXiv:2303.10798]; it can tile the plan ... Full text Cite

Evolution of force networks during stick-slip motion of an intruder in a granular material: Topological measures extracted from experimental data.

Journal Article Physical review. E · November 2023 In quasi-two-dimensional experiments with photoelastic particles confined to an annular region, an intruder constrained to move in a circular path halfway between the annular walls experiences stick-slip dynamics. We discuss the response of the granular me ... Full text Cite

Quasicrystalline structure of the Smith monotile tilings

Preprint · May 1, 2023 Link to item Cite

Microscopic reversibility and emergent elasticity in ultrastable granular systems

Journal Article Frontiers in Physics · November 28, 2022 In a recent paper (Zhao et al., Phys Rev X, 2022, 12: 031,021), we reported experimental observations of “ultrastable” states in a shear-jammed granular system subjected to small-amplitude cyclic shear. In such states, all the particle positions and contac ... Full text Cite

Stick-Slip Dynamics in a Granular Material With Varying Grain Angularity

Journal Article Frontiers in Physics · July 15, 2022 Experiments, simulations, and theoretical treatments of granular materials typically feature circular or elliptical grains. However, grains found in natural systems often have flat faces that introduce local rotational constraints; these rotational constra ... Full text Cite

Ultrastable Shear-Jammed Granular Material

Journal Article Physical Review X · July 1, 2022 Dry granular materials, such as sand, gravel, pills, or agricultural grains, can become rigid when compressed or sheared. Under isotropic compression, the material reaches a certain jamming density and then resists further compression. Shear jamming occurs ... Full text Cite

Universal features of the stick-slip dynamics of an intruder moving through a confined granular medium.

Journal Article Physical review. E · April 2022 Experiments and simulations of an intruder dragged by a spring through a two-dimensional annulus of granular material exhibit robust force fluctuations. At low packing fractions (ϕ<ϕ_{0}), the intruder clears an open channel. Above ϕ_{0}, stick-slip dynami ... Full text Cite

Random logic networks: From classical Boolean to quantum dynamics.

Journal Article Physical review. E · December 2021 We investigate dynamical properties of a quantum generalization of classical reversible Boolean networks. The state of each node is encoded as a single qubit, and classical Boolean logic operations are supplemented by controlled bit-flip and Hadamard opera ... Full text Open Access Cite

Two Approaches to Quantification of Force Networks in Particulate Systems

Journal Article Journal of Engineering Mechanics · November 1, 2021 The interactions between particles in dense particulate systems are organized in force networks, mesoscale features that influence the macroscopic response to applied stresses. The detailed structure of these networks is, however, difficult to extract from ... Full text Cite

Stress propagation in locally loaded packings of disks and pentagons.

Journal Article Soft matter · November 2021 The mechanical strength and flow of granular materials can depend strongly on the shapes of individual grains. We report quantitative results obtained from photoelasticimetry experiments on locally loaded, quasi-two-dimensional granular packings of either ... Full text Open Access Cite

Particle dynamics in two-dimensional point-loaded granular media composed of circular or pentagonal grains

Conference Powders and Grains 2021 - 9th International Conference on Micromechanics on Granular Media · June 7, 2021 Granular packings exhibit significant changes in rheological and structural properties when the rotational symmetry of spherical or circular particles is broken. Here, we report on experiments exploring the differences in dynamics of a grain-scale intruder ... Full text Cite

Ultra-stable shear jammed granular material

Journal Article Physical Review X · May 1, 2021 Dry granular materials such as sand, gravel, pills, or agricultural grains, can become rigid when compressed or sheared. At low density, one can distort the shape of a container of granular material without encountering any resistance. Under isotropic comp ... Link to item Cite

Static and dynamic features of granular material failure due to upward pulling of a buried sphere by a slowly increasing force.

Journal Article Soft matter · March 2021 A spherical intruder embedded in a confined granular column is extracted by pulling it upward by an attached string. As the tension of the string gradually increases, a failure event occurs at a certain pulling force, leading to rapid upward acceleration o ... Full text Cite

Yielding, rigidity, and tensile stress in sheared columns of hexapod granules.

Journal Article Physical review. E · June 2020 Granular packings of nonconvex or elongated particles can form freestanding structures like walls or arches. For some particle shapes, such as staples, the rigidity arises from interlocking of pairs of particles, but the origins of rigidity for noninterloc ... Full text Open Access Cite

Intruder in a two-dimensional granular system: Effects of dynamic and static basal friction on stick-slip and clogging dynamics.

Journal Article Physical review. E · January 2020 We present simulation results for an intruder pulled through a two-dimensional granular system by a spring using a model designed to mimic the experiments described by Kozlowski et al. [Phys. Rev. E 100, 032905 (2019)2470-004510.1103/PhysRevE.100.032905]. ... Full text Cite

Jamming transition in non-spherical particle systems: pentagons versus disks

Journal Article Granular Matter · November 1, 2019 We investigate the jamming transition in a quasi-2D granular material composed of regular pentagons or disks subjected to quasistatic uniaxial compression. We report six major findings based on experiments with monodisperse photoelastic particles with stat ... Full text Cite

Jamming by shear in a dilating granular system

Journal Article Granular Matter · November 1, 2019 Jamming can occur in frictional granular materials undergoing shear at a fixed packing fraction, ϕ, within a range below the isotropic jamming point, with the amount of strain required to induce jamming, γ, increasing with decreasing ϕ. We are interested i ... Full text Cite

Shear-Jammed, Fragile, and Steady States in Homogeneously Strained Granular Materials.

Journal Article Physical review letters · October 2019 We study the jamming phase diagram of sheared granular material using a novel Couette shear setup with a multiring bottom. The setup uses small basal friction forces to apply a volume-conserving linear shear with no shear band to a granular system composed ... Full text Cite

Dynamics of a grain-scale intruder in a two-dimensional granular medium with and without basal friction.

Journal Article Physical review. E · September 2019 We report on a series of experiments in which a grain-sized intruder is pushed by a spring through a two-dimensional granular material composed of photoelastic disks in a Couette geometry. We study the intruder dynamics as a function of packing fraction fo ... Full text Cite

Seismicity in sheared granular matter.

Journal Article Physical review. E · May 2019 We report on experiments investigating the dynamics of a slider that is pulled by a spring across a granular medium consisting of a vertical layer of photoelastic disks. The motion proceeds through a sequence of discrete events, analogous to seismic shocks ... Full text Cite

Quasicrystalline structure of the hat monotile tilings

Evolution of force networks during stick-slip motion of an intruder in a granular material: Topological measures extracted from experimental data.

Quasicrystalline structure of the Smith monotile tilings

Preprint · May 1, 2023 Link to item Cite

Microscopic reversibility and emergent elasticity in ultrastable granular systems

Stick-Slip Dynamics in a Granular Material With Varying Grain Angularity

Ultrastable Shear-Jammed Granular Material

Universal features of the stick-slip dynamics of an intruder moving through a confined granular medium.

Random logic networks: From classical Boolean to quantum dynamics.

Two Approaches to Quantification of Force Networks in Particulate Systems

Stress propagation in locally loaded packings of disks and pentagons.

Particle dynamics in two-dimensional point-loaded granular media composed of circular or pentagonal grains

Ultra-stable shear jammed granular material

Static and dynamic features of granular material failure due to upward pulling of a buried sphere by a slowly increasing force.

Yielding, rigidity, and tensile stress in sheared columns of hexapod granules.

Intruder in a two-dimensional granular system: Effects of dynamic and static basal friction on stick-slip and clogging dynamics.

Jamming transition in non-spherical particle systems: pentagons versus disks

Jamming by shear in a dilating granular system

Shear-Jammed, Fragile, and Steady States in Homogeneously Strained Granular Materials.

Dynamics of a grain-scale intruder in a two-dimensional granular medium with and without basal friction.

Seismicity in sheared granular matter.

Hyperuniformity and anti-hyperuniformity in one-dimensional substitution tilings.

Journal Article Acta crystallographica. Section A, Foundations and advances · January 2019 This work considers the scaling properties characterizing the hyperuniformity (or anti-hyperuniformity) of long-wavelength fluctuations in a broad class of one-dimensional substitution tilings. A simple argument is presented which predicts the exponent α g ... Full text Cite

Robert Paul Behringer

Journal Article Physics Today · December 1, 2018 Full text Cite

Phase diagram and aggregation dynamics of a monolayer of paramagnetic colloids.

Journal Article Physical review. E · May 2017 We have developed a tunable colloidal system and a corresponding theoretical model for studying the phase behavior of particles assembling under the influence of long-range magnetic interactions. A monolayer of paramagnetic particles is subjected to a spat ... Full text Open Access Cite

Hyperuniformity of quasicrystals

Journal Article Physical Review B · February 23, 2017 Hyperuniform systems, which include crystals, quasicrystals, and special disordered systems, have attracted considerable recent attention, but rigorous analyses of the hyperuniformity of quasicrystals have been lacking because the support of the spectral i ... Full text Cite

Mechanical graphene

Journal Article New Journal of Physics · February 7, 2017 Full text Cite

Formation of limit-periodic structures by quadrupole particles confined to a triangular lattice

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · January 10, 2017 We have performed Monte Carlo (MC) simulations on two-dimensional systems of quadrupole particles confined to a triangular lattice in order to determine the conditions that permit the formation of a limit-periodic phase. We have found that limit-periodic s ... Full text Cite

Local growth of icosahedral quasicrystalline tilings

Journal Article Physical Review B · July 14, 2016 Icosahedral quasicrystals (IQCs) with extremely high degrees of translational order have been produced in the laboratory and found in naturally occurring minerals, yet questions remain about how IQCs form. In particular, the fundamental question of how loc ... Full text Cite

Sparse phonon modes of a limit-periodic structure

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 1, 2016 Limit-periodic structures are well ordered but nonperiodic, and hence have nontrivial vibrational modes. We study a ball and spring model with a limit-periodic pattern of spring stiffnesses and identify a set of extended modes with arbitrarily low particip ... Full text Link to item Cite

Hard sphere packings within cylinders.

Journal Article Soft matter · March 2016 Arrangements of identical hard spheres confined to a cylinder with hard walls have been used to model experimental systems, such as fullerenes in nanotubes and colloidal wire assembly. Finding the densest configurations, called close packings, of hard sphe ... Full text Open Access Cite

Erratum: Emergence of limit-periodic order in tiling models (Physical Review E - Statistical, Nonlinear, and Soft Matter Physics (2014) 90 (012136))

Journal Article Physical Review E · February 29, 2016 Full text Open Access Cite

Phase transformations in binary colloidal monolayers.

Journal Article Soft matter · March 2015 Phase transformations can be difficult to characterize at the microscopic level due to the inability to directly observe individual atomic motions. Model colloidal systems, by contrast, permit the direct observation of individual particle dynamics and of c ... Full text Open Access Cite

Regulatory logic and pattern formation in the early sea urchin embryo.

Journal Article Journal of theoretical biology · December 2014 We model the endomesoderm tissue specification process in the vegetal half of the early sea urchin embryo using Boolean models with continuous-time updating to represent the regulatory network that controls gene expression. Our models assume that the netwo ... Full text Cite

Delayed transition to new cell fates during cellular reprogramming.

Journal Article Developmental biology · July 2014 In many embryos specification toward one cell fate can be diverted to a different cell fate through a reprogramming process. Understanding how that process works will reveal insights into the developmental regulatory logic that emerged from evolution. In t ... Full text Cite

Emergence of limit-periodic order in tiling models.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · July 2014 A two-dimensional (2D) lattice model defined on a triangular lattice with nearest- and next-nearest-neighbor interactions based on the Taylor-Socolar monotile is known to have a limit-periodic ground state. The system reaches that state during a slow quenc ... Full text Open Access Cite

Causal structure of oscillations in gene regulatory networks: Boolean analysis of ordinary differential equation attractors.

Journal Article Chaos (Woodbury, N.Y.) · June 2013 A common approach to the modeling of gene regulatory networks is to represent activating or repressing interactions using ordinary differential equations for target gene concentrations that include Hill function dependences on regulator gene concentrations ... Full text Cite

Magnetically directed assembly and dynamic manipulation of binary colloidal crystals

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · April 7, 2013 Link to item Cite

Autonomous Boolean modelling of developmental gene regulatory networks.

Journal Article Journal of the Royal Society, Interface · January 2013 During early embryonic development, a network of regulatory interactions among genes dynamically determines a pattern of differentiated tissues. We show that important timing information associated with the interactions can be faithfully represented in aut ... Full text Cite

Hierarchical freezing of limit-periodic structure

Journal Article Physical Review E · November 12, 2012 Cite

Quantifying the complexity of random Boolean networks.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · June 2012 We study two measures of the complexity of heterogeneous extended systems, taking random Boolean networks as prototypical cases. A measure defined by Shalizi et al. for cellular automata, based on a criterion for optimal statistical prediction [Shalizi et ... Full text Cite

Forcing nonperiodicity with a single tile

Journal Article The Mathematical Intelligencer · March 2012 An aperiodic prototile is a shape for which infinitely many copies can be arranged to fill Euclidean space completely with no overlaps, but not in a periodic pattern. Tiling theorists refer to such a prototile as an "einstein" (a German pun on "one stone") ... Full text Cite

Graph fission in an evolving voter model.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · March 2012 We consider a simplified model of a social network in which individuals have one of two opinions (called 0 and 1) and their opinions and the network connections coevolve. Edges are picked at random. If the two connected individuals hold different opinions ... Full text Cite

Binary colloidal structures assembled through Ising interactions

Journal Article Nature Communications · 2012 New methods for inducing microscopic particles to assemble into useful macroscopic structures could open pathways for fabricating complex materials that cannot be produced by lithographic methods. Here we demonstrate a colloidal assembly technique that use ... Full text Link to item Cite

Hierarchical freezing in a lattice model.

Journal Article Physical review letters · January 2012 A certain two-dimensional lattice model with nearest and next-nearest neighbor interactions is known to have a limit-periodic ground state. We show that during a slow quench from the high temperature, disordered phase, the ground state emerges through an i ... Full text Cite

Comparison of autonomous Boolean network dynamics and ODE models

Journal Article Chaos · 2012 Cite

Local action, global impact: forcing nonperiodicity with a single structural unit.

Journal Article Chaos (Woodbury, N.Y.) · December 2011 Full text Cite

An aperiodic hexagonal tile

Journal Article J. Comb. Theory Ser. A · November 2011 Full text Cite

Reliability of transcriptional cycles and the yeast cell-cycle oscillator.

Journal Article PLoS computational biology · July 2010 A recently published transcriptional oscillator associated with the yeast cell cycle provides clues and raises questions about the mechanisms underlying autonomous cyclic processes in cells. Unlike other biological and synthetic oscillatory networks in the ... Full text Open Access Cite

On the origin of chaos in autonomous Boolean networks.

Journal Article Philosophical transactions. Series A, Mathematical, physical, and engineering sciences · January 2010 We undertake a systematic study of the dynamics of Boolean networks to determine the origin of chaos observed in recent experiments. Networks with nodes consisting of ideal logic gates are known to display either steady states, periodic behaviour or an ult ... Full text Cite

Reliability of transcriptional cycles and the yeast cell-cycle oscillator

Journal Article PLoS Computational Biology · January 1, 2010 A recently published transcriptional oscillator associated with the yeast cell cycle provides clues and raises questions about the mechanisms underlying autonomous cyclic processes in cells. Unlike other biological and synthetic oscillatory networks in the ... Full text Cite

Boolean chaos.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · October 2009 We observe deterministic chaos in a simple network of electronic logic gates that are not regulated by a clocking signal. The resulting power spectrum is ultrawide band, extending from dc to beyond 2 GHz. The observed behavior is reproduced qualitatively u ... Full text Cite

Boolean modeling of collective effects in complex networks.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · June 2009 Complex systems are often modeled as Boolean networks in attempts to capture their logical structure and reveal its dynamical consequences. Approximating the dynamics of continuous variables by discrete values and Boolean logic gates may, however, introduc ... Full text Cite

Global control of cell-cycle transcription by coupled CDK and network oscillators.

Journal Article Nature · June 2008 A significant fraction of the Saccharomyces cerevisiae genome is transcribed periodically during the cell division cycle, indicating that properly timed gene expression is important for regulating cell-cycle events. Genomic analyses of the localization and ... Full text Cite

Time-Delay Control for Discrete Maps

Journal Article · May 20, 2008 This chapter is intended as a pedagogical introduction to discrete time delayed feedback methods. It is neither a comprehensive review, nor a presentation of dramatic new results. It does, on the other hand, organize known results in a self-contained manne ... Full text Cite

Nonlinear elastic stress response in granular packings.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · March 2008 We study the nonlinear elastic response of a two-dimensional material to a localized boundary force, with the particular goal of understanding the differences observed between isotropic granular materials and those with hexagonal anisotropy. Corrections to ... Full text Cite

Mutual information in random Boolean models of regulatory networks.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · January 2008 The amount of mutual information contained in the time series of two elements gives a measure of how well their activities are coordinated. In a large, complex network of interacting elements, such as a genetic regulatory network within a cell, the average ... Full text Cite

Attractors in continuous and Boolean networks.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · October 2007 We study the stable attractors of a class of continuous dynamical systems that may be idealized as networks of Boolean elements, with the goal of determining which Boolean attractors, if any, are good approximations of the attractors of generic continuous ... Full text Cite

Control of electrical alternans in simulations of paced myocardium using extended time-delay autosynchronization.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · October 2007 Experimental studies have linked alternans, an abnormal beat-to-beat alternation of cardiac action potential duration, to the genesis of lethal arrhythmias such as ventricular fibrillation. Prior studies have considered various closed-loop feedback control ... Full text Cite

Erratum: The hexagonal parquet tiling, k-isohedral monotiles with arbitrarily large k (The Mathematical Intelligencer 29:2 (33-38))

Journal Article Mathematical Intelligencer · September 1, 2007 Full text Cite

Network analysis of the state space of discrete dynamical systems.

Journal Article Physical review letters · May 2007 We study networks representing the dynamics of elementary 1D cellular automata (CA) on finite lattices. We analyze scaling behaviors of both local and global network properties as a function of system size. The scaling of the largest node in-degree is obta ... Full text Cite

The hexagonal parquet tiling k-isohedral monotiles with arbitrarily large k

Journal Article Mathematical Intelligencer · March 1, 2007 Full text Cite

Exhaustive percolation on random networks.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · September 2006 We consider propagation models that describe the spreading of an attribute, called "damage," through the nodes of a random network. In some systems, the average fraction of nodes that remain undamaged vanishes in the large system limit, a phenomenon we ref ... Full text Cite

Network growth models and genetic regulatory networks.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · March 2006 We study a class of growth algorithms for directed graphs that are candidate models for the evolution of genetic regulatory networks. The algorithms involve partial duplication of nodes and their links, together with the innovation of new links, allowing f ... Full text Cite

Force distributions in a triangular lattice of rigid bars.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · September 2005 We study the uniformly weighted ensemble of force balanced configurations on a triangular network of nontensile contact forces. For periodic boundary conditions corresponding to isotropic compressive stress, we find that the probability distribution for si ... Full text Cite

Modeling pathways of differentiation in genetic regulatory networks with Boolean networks

Journal Article Complexity · January 1, 2005 We have carried out the first examination of pathways of cell differentiation in model genetic networks in which cell types are assumed to be attractors of the nonlinear dynamics, and differentiation corresponds to a transition of the cell to a new basin o ... Full text Cite

Design and robustness of delayed feedback controllers for discrete systems

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · May 1, 2004 A matrix form of time-delay feedback control in the context of discrete time maps of high dimension was studied. Time-delay feedback controllers containing only static elements can be designed to achieve identical linear stability properties, in almost all ... Cite

Design and robustness of delayed feedback controllers for discrete systems.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · May 2004 We study a matrix form of time-delay feedback control in the context of discrete time maps of high dimension. In almost all cases where standard proportional feedback control methods can achieve control, time-delay feedback controllers containing only stat ... Full text Cite

Stability domains for time-delay feedback control with latency.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · September 2003 We generalize a known analytical method for determining the stability of periodic orbits controlled by time-delay feedback methods when latencies associated with the generation and injection of the feedback signal cannot be ignored. We discuss the case of ... Full text Cite

Anisotropy in granular media: classical elasticity and directed-force chain network.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · March 2003 A general approach is presented for understanding the stress response function in anisotropic granular layers in two dimensions. The formalism accommodates both classical anisotropic elasticity theory and linear theories of anisotropic directed-force chain ... Full text Cite

Scaling in ordered and critical random boolean networks.

Journal Article Physical review letters · February 2003 Random Boolean networks, originally invented as models of genetic regulatory networks, are simple models for a broad class of complex systems that show rich dynamical structures. From a biological perspective, the most interesting networks lie at or near a ... Full text Cite

Chaos

Chapter · 2003 Full text Cite

Discrete models of force chain networks

Journal Article Discrete and Continuous Dynamical Systems - Series B · January 1, 2003 A fundamental property of any material is its response to a localized stress applied at a boundary. For granular materials consisting of hard, cohesionless particles, not even the general form of the stress response is known. Directed force chain networks ... Full text Cite

Anisotropy in granular media: Classical elasticity and directed-force chain network

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · 2003 A general framework that covers both classical anisotropic elasticity theory and a generally anisotropic "pseudoelasticity" theory, that appears within a linearized treatment of directed-force chain networks is presented. It is shown how the formalism appl ... Cite

Stability domains for time-delay feedback control with latency

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · 2003 The stability of periodic orbits controlled by time-delay feedback methods with latency was determined. Floquet theory and first order theory were used to derive nonlinear shapes from parametrized plane. It was found that Floquet modes, that contributed si ... Cite

`Comparison of time-delayed feedback schemes for spatio-temporal control of chaos

Journal Article Phys. Rev. E · December 2002 Cite

Comparison of time-delayed feedback schemes for spatiotemporal control of chaos in a reaction-diffusion system with global coupling.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · July 2002 Time-delayed feedback control for stabilizing time periodic spatial patterns is investigated in a generic reaction-diffusion system with global coupling. We focus on the case of low-dimensional chaos where unstable patterns admit only a single unstable mod ... Full text Cite

Directed force chain networks and stress response in static granular materials.

Journal Article The European physical journal. E, Soft matter · April 2002 A theory of stress fields in two-dimensional granular materials based on directed force chain networks is presented. A general Boltzmann equation for the densities of force chains in different directions is proposed and a complete solution is obtained for ... Full text Cite

Erratum: Directed force chain networks and stress response in static granular materials (The European Physical Journal E (2002) 7 (353-370))

Journal Article European Physical Journal E · January 1, 2002 Full text Cite

Limitation on stabilizing plane waves via time-delay feedback.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · November 2001 Previous work has demonstrated the possibility of stabilizing plane wave solutions of one-dimensional systems using a spatially local form of time-delayed feedback. We show that the natural extension of this method to two-dimensional systems fails due to t ... Full text Cite

Evolution in a spatially structured population subject to rare epidemics.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · April 2001 We study a model that gives rise to spatially inhomogeneous population densities in a system of host individuals subject to rare, randomly distributed disease events. For stationary hosts that disperse offspring over short distances, evolutionary dynamics ... Full text Cite

Delayed feedback control of a paced excitable oscillator

Journal Article International Journal of Bifurcation and Chaos in Applied Sciences and Engineering · January 1, 2000 A simple numerical experiment on Fitzhugh-Nagumo equations demonstrates that time-delay feedback methods can stabilize regular behavior in a paced, excitable oscillator without using large applied pulses. The method is robust against slow variations in the ... Full text Cite

Selection for intermediate mortality and reproduction rates in a spatially structured population.

Journal Article Proceedings. Biological sciences · December 1999 How local interactions influence both population and evolutionary dynamics is currently a key topic in theoretical ecology. We use a 'well-mixed' analytical model and spatially explicit individual-based models to investigate a system where a population is ... Full text Cite

Force distribution in a scalar model for noncohesive granular material.

Journal Article Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics · August 1999 We study a scalar lattice model for intergrain forces in static, noncohesive, granular materials, obtaining two primary results: (i) The applied stress as a function of overall strain shows a power law dependence with a nontrivial exponent, which moreover ... Full text Cite

Average stresses and force fluctuations in noncohesive granular materials

Journal Article PHYSICAL REVIEW E · March 1, 1998 Full text Link to item Cite

Analysis and comparison of multiple-delay schemes for controlling unstable fixed points of discrete maps

Journal Article Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics · January 1, 1998 We investigate theoretically the stabilization of a fixed point of a discrete one-dimensional nonlinear map by applying small perturbations to an accessible system parameter or variable. The size of the perturbations is determined in real time using feedba ... Full text Cite

Failure of linear control in noisy coupled map lattices

Journal Article Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics · January 1, 1998 We study a one-dimensional ring of diffusively coupled logistic maps in the vicinity of an unstable, spatially homogeneous fixed point. The failure of linear controllers due to additive noise is discussed with the aim of clarifying the failure mechanism. A ... Full text Cite

Controlling chaos in a fast diode resonator using extended time-delay autosynchronization: Experimental observations and theoretical analysis.

Journal Article Chaos (Woodbury, N.Y.) · December 1997 We stabilize unstable periodic orbits of a fast diode resonator driven at 10.1 MHz (corresponding to a drive period under 100 ns) using extended time-delay autosynchronization. Stabilization is achieved by feedback of an error signal that is proportional t ... Full text Cite

Comment on Dynamic Control of Cardiac Alternans

Journal Article Physical Review Letters · 1997 Cite

Controlling extended systems with spatially filtered, time-delayed feedback

Journal Article Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics · January 1, 1997 We investigate a control technique for spatially extended systems combining spatial filtering with a previously studied form of time-delay feedback. The scheme is naturally suited to real-time control of optical systems. We apply the control scheme to a mo ... Full text Cite

Controlling spatiotemporal dynamics with time-delay feedback

Journal Article Physical Review E · July 1, 1996 Full text Cite

Stability of periodic orbits controlled by time-delay feedback

Journal Article Physics Letters, Section A: General, Atomic and Solid State Physics · January 1, 1996 Extended time-delay auto-synchronization (ETDAS) is a promising technique for stabilizing unstable periodic orbits in low-dimensional dynamical systems. The technique involves continuous feedback of signals delayed by multiples of the orbit's period in a m ... Full text Cite

Stabilizing unstable periodic orbits in fast dynamical systems.

Journal Article Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics · October 1994 Full text Cite

Stabilizing unstable periodic orbits in a fast diode resonator using continuous time-delay autosynchronization.

Journal Article Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics · September 1994 Full text Cite

[title field missing]

Journal Article Phys. Rev. E · 1994 Full text Cite

Scale invariance of nonconserved quantities in driven systems.

Journal Article Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics · August 1993 Full text Cite

ON SELF-ORGANIZED CRITICALITY IN NONCONSERVING SYSTEMS

Journal Article PHYSICAL REVIEW E · April 1, 1993 Full text Link to item Cite

Surface fluctuations and criticality in a class of one-dimensional sandpile models.

Journal Article Physical review. A, Atomic, molecular, and optical physics · October 1992 Full text Cite

Theory of Packings of Identical Hard Disks Generated by Ballistic Deposition

Journal Article Europhysics Letters (EPL) · February 14, 1992 Full text Cite

Comment on "Scalings of growing self-organized surfaces"

Journal Article Physical review letters · February 1992 Full text Cite

Surface Fluctuations and Criticality in a Class of 1D Sandpile Models

Journal Article Phys. Rev. A (RC) · 1992 Cite

Growth Rules For Quasicrystals

Chapter · October 1991 Full text Cite

Weak matching rules for quasicrystals

Journal Article Communications in Mathematical Physics · May 1, 1990 Weak matching rules for a quasicrystalline tiling are local rules that ensure that fluctuations in "perp-space" are uniformly bounded. It is shown here that weak matching rules exist for N-fold symmetric tilings, where N is any integer not divisible by fou ... Full text Cite

The Alternation Condition and 2D Quasicrystals

Chapter · 1990 Full text Cite

Simple octagonal and dodecagonal quasicrystals.

Journal Article Physical review. B, Condensed matter · May 1989 Full text Cite

Onoda etal. reply.

Journal Article Physical review letters · March 1989 Full text Cite

Reply to Comment on PRL

Journal Article Phys. Rev. Lett. · 1989 Cite

Growing perfect quasicrystals.

Journal Article Physical review letters · June 1988 Full text Cite

Explanation of peak shapes observed in diffraction from icosahedral quasicrystals.

Journal Article Physical review letters · July 1987 Full text Cite

Distortion and peak broadening in quasicrystal diffraction patterns.

Journal Article Physical review letters · September 1986 Full text Cite

Phonons, phasons, and dislocations in quasicrystals.

Journal Article Physical review. B, Condensed matter · September 1986 Full text Cite

Quasicrystals. II. Unit-cell configurations.

Journal Article Physical review. B, Condensed matter · July 1986 Full text Cite

Phason Strain in Quasicrystals

Journal Article Journal de Physique · 1986 Cite

Quasicrystals II: Unit Cell Structures

Journal Article Phys. Rev. B · 1986 Cite

Quasicrystals with arbitrary orientational symmetry.

Journal Article Physical review. B, Condensed matter · October 1985 Full text Cite

Numerical integration of the time evolution operator: Excited‐state dynamics in conjugated molecules

Journal Article International Journal of Quantum Chemistry · January 1, 1984 Two simple and manageable schemes for integrating the time evolution operator e−iHt are discussed and applied to study vibronic effects in photoemission and optical excitation of model conjugated molecules. Copyright © 1984 John Wiley & Sons, Inc. ... Full text Cite

Trajectory divergence for coupled relaxation oscillators: Measurements and models

Journal Article Journal of Statistical Physics · September 1, 1980 The exponential divergence of nearby phase space trajectories is a hallmark of nonperiodic (chaotic) behavior in dynamical systems. We present the first laboratory of measurements of divergence rates (or characteristic exponents), using a system of coupled ... Full text Cite

Dispersion Tuning and Route Reconfiguration of Acoustic Waves in Valley Topological Phononic Crystals

Journal Article Nature Communications The valley degree of freedom in crystals offers great potential for manipulating classical waves; however, few studies have investigated valley states with complex wavenumbers, valley states in graded systems, or dispersion tuning for valley states. Here, ... Cite

Intruder in a two-dimensional granular system: Effects of dynamic and static basal friction on stick-slip and clogging dynamics

Journal Article Physical Review E Cite

Nonlinear Dynamical Systems

Chapter Full text Cite