FLOCKING STATES OF SELF-PROPELLING PARTICLES IN FREE SPACE

2007 ◽  
Vol 21 (23n24) ◽  
pp. 3954-3959 ◽  
Author(s):  
KWAN-TAI LEUNG ◽  
HSUAN-YI CHEN
Keyword(s):  
Continuum Model ◽  
Stationary Phases ◽  
Formation Flight ◽  
The Self ◽  
Particle Interactions ◽  
Simple Rules ◽  
Range Alignment ◽  
Steady State Solutions ◽  
Present Particle ◽  
Flocking Behavior

We present particle-based simulations for the flocking behavior of self-propelling particles. Built upon previous models, our models include realistic but simple rules for the self-propelling, drag, and inter-particle interactions. Depending on both the strength and range of the interactions, a host of stationary phases appear, including independent wandering, formation flight, swarm, and rotating vortex. Of particular interest, we determine that the rotating flock can only arise in the absence of long-range alignment. We also construct a phenomenological continuum model and obtain steady-state solutions for the rotating state.

Large-Scale Self-Assembly in Weakly-Flocculated Suspensions

2019 ◽  
Vol 4 (1) ◽  
pp. 68-74
Author(s):  
Aleš Dakskobler ◽  
Matjaz Valant
Keyword(s):  
Self Assembly ◽  
Shear Force ◽  
Large Scale ◽  
Hard Spheres ◽  
Colloidal Crystals ◽  
The Self ◽  
Spherical Particles ◽  
Particle Interactions ◽  
Concentrated Suspensions ◽  
Average Angle

Background: Studies on the formation of colloidal crystals in concentrated suspensions have mainly been based on dispersed suspensions with a repulsive inter-particle potential of hard or nearly hard spheres. The self-assembly in weakly-flocculated suspensions has still been unrealized. Here, we report on the formation of ordered structures in concentrated suspensions of nearly-hard spherical particles with weakly-attractive inter-particle interactions that are an order of magnitude higher than the particles’ thermal energy. Methods: In our case, the self-assembly in such suspensions is not thermodynamically driven, but an external shear force must be applied. The driving force for the particles’ ordering is an increase in the inter-particle interactions. This manifests itself in a decrease in the average angle between the interparticle interaction direction and the applied shear stress direction. Results: For a successful ordering into a large-scale closed packed assembly, the external shear force must not exceed the inter-particle attractive interaction for the minimum possible average angle (as in the closed packed structures) but be high enough to enable the particles to move in the highly loaded suspension. Conclusion: The developed method for the self-assembly of the weakly flocculated systems can be applied very generally e.g. a control over a composition of heterogeneous colloidal crystals, manufacturing of the large-scale photonic crystals or preparation of very densely packed compacts of particles needed for the production of sintered ceramics.

Observation of Synchronization Phenomena in Structured Flocking Behavior

2013 ◽  
Vol 17 (5) ◽  
pp. 715-720 ◽  
Author(s):  
Sho Yamauchi ◽  
◽  
Hidenori Kawamura ◽  
Keiji Suzuki
Keyword(s):  
Autonomous System ◽  
Consensus Problem ◽  
Multi Agent Systems ◽  
Agent Systems ◽  
Simple Rules ◽  
Flexible Behavior ◽  
Multi Agent ◽  
Lattice Formation ◽  
Arbitrary Lattice ◽  
Flocking Behavior

Flocking algorithms for multi-agent systems are distributed algorithms that generate complex formational movement despite having simple rules for each agent. These algorithms, known as swarmintelligence, are flexible and robust. However, to exploit these features to generate flexible behavior in an autonomous system, greater flexibility is needed. To achieve this, these algorithms are extended to enable arbitrary lattice formation. In addition, extended flocking algorithms can be assumed to be the aggregation of oscillators and observed the behavior of synchronization. It is difficult to explain the behavior of extended flocking algorithms as a consensus problem but, by assuming the flock as the set of oscillators, it can be explained as a synchronization phenomenon.

Reinforcement Learning Scheme for Flocking Behavior Emergence

2007 ◽  
Vol 11 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Koichiro Morihiro ◽  
◽  
Teijiro Isokawa ◽  
Haruhiko Nishimura ◽  
Masahito Tomimasu ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Collective Behavior ◽  
A Priori ◽  
The Self ◽  
Self Organized ◽  
Learning Scheme ◽  
Fish Schooling ◽  
Grouping Behavior ◽  
Flocking Behavior ◽  
New Framework

Collective behavior such as bird flocking, land animal herding, and fish schooling is well known in nature. Many observations have shown that there are no leaders to control the behavior of a group. Several models have been proposed for describing the grouping behavior, which we regard as a distinctive example of aggregate motions. In these models, a fixed rule is provided for each of the individuals a priori for their interactions in a reductive and rigid manner. In contrast, we propose a new framework for the self-organized grouping of agents by reinforcement learning. It is important to introduce a learning scheme for causing collective behavior in artificial autonomous distributed systems. The behavior of agents is demonstrated and evaluated through computer simulations and it is shown that their grouping behavior emerges as a result of learning.

scholarly journals Continuum modeling of hydrodynamic particle–particle interactions in microfluidic high-concentration suspensions

Lab on a Chip ◽  
2016 ◽  
Vol 16 (7) ◽  
pp. 1178-1188 ◽  
Author(s):  
Mikkel W. H. Ley ◽  
Henrik Bruus
Keyword(s):  
Continuum Model ◽  
Particle Interactions ◽  
Continuum Modeling ◽  
High Concentration ◽  
Numerical Studies

A continuum model is established for numerical studies of hydrodynamic particle–particle interactions in microfluidic high-concentration suspensions.

scholarly journals A dynamic preferred direction model for the self-organization dynamics of bacterial microfluidic pumping

Soft Matter ◽  
2019 ◽  
Vol 15 (9) ◽  
pp. 2032-2042
Author(s):  
Daniel Svenšek ◽  
Harald Pleiner ◽  
Helmut R. Brand
Keyword(s):  
Continuum Model ◽  
The Self ◽  
Channel Width ◽  
Self Organization ◽  
Preferred Direction ◽  
Set Up ◽  
Direction Model ◽  
Organization Mechanism ◽  
Microfluidic Pumping

We set up a continuum model capable of describing the pumping self-organization mechanism of the bacteria and quantifying it to the extent that an agreement with the experimentally observed channel width dependence of the pumping is reached.

scholarly journals Classification and Evolutionary Trends of Icosahedral Viral Capsids

2008 ◽  
Vol 9 (3-4) ◽  
pp. 175-181 ◽  
Author(s):  
Richard Kerner
Keyword(s):  
Building Blocks ◽  
The Self ◽  
Self Organization ◽  
Evolutionary Trends ◽  
Viral Capsids ◽  
Exact Number ◽  
Evolution Of Viruses ◽  
Simple Rules ◽  
Elementary Building

A classification of icosahedral viral capsids is proposed. We show how the self-organization of capsids during their formation implies a definite composition of their elementary building blocks. The exact number of hexamers with three different admissible symmetries is related to capsids' sizes, labelled by theirT-numbers. Simple rules determining these numbers for each value ofTare deduced and certain consequences concerning the probabilities of mutations and evolution of viruses are discussed.

scholarly journals Surface-triggered cascade reactions between DNA linkers direct the self-assembly of colloidal crystals of controllable thickness

Nanoscale ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 5450-5459 ◽  
Author(s):  
Pritam Kumar Jana ◽  
Bortolo Matteo Mognetti
Keyword(s):  
Self Assembly ◽  
Colloidal Crystals ◽  
Cascade Reactions ◽  
The Self ◽  
Particle Interactions ◽  
Functionalized Surfaces ◽  
Layer Deposition

Functionalized surfaces direct colloidal layer deposition by enhancing particle–particle interactions.

The engagement continuum model using corporate social responsibility as an intervention for sustained employee engagement

2015 ◽  
Vol 39 (3) ◽  
pp. 182-202 ◽  
Author(s):  
Marie Anttonitte Valentin ◽  
Celestino C Valentin ◽  
Fredrick Muyia Nafukho
Keyword(s):  
Corporate Social Responsibility ◽  
Social Responsibility ◽  
Employee Engagement ◽  
Continuum Model ◽  
Self Determination Theory ◽  
The Self ◽  
Self Determination ◽  
Motivating Factors ◽  
Content Type ◽  
Corporate Social

Purpose – The purpose of this paper is to explore implications of motivational potential that are highly correlated to the self-determination theory (SDT) (intrinsic motivating factors), in relation to corporate social responsibility (CSR). This paper specifies key antecedents of engagement within the theoretical framework of the self-determination theory as it relates to employee engagement and CSR. Design/methodology/approach – The methods used for the purpose of this paper include a review of the relevant literature utilizing the descriptors of employee engagement, SDT and CSR. Alternative descriptors were not queried. The authors then selected articles that were found to be most cited, reviewed such articles and began to analyze the literature, synthesize and formulate connections. Findings – Based on research findings, a conceptual model was formulated and posited for research and practice. It is demonstrated in the paper that employee engagement has a wide range of benefits for all involved and focuses on key antecedents of engagement created through CSR initiatives and intrinsic motivating factors as pointed out from SDT, which may serve to provide a comprehensive representation of the likely influences of intrinsic motivating drivers on employee engagement. Research limitations/implications – The main limitations of this paper is that it is conceptual in nature and, hence, the need for a study designed to empirically test the conceptual model developed in this research. Originality/value – The result and contribution to the field of human resource development is the development of the engagement continuum model from which employee engagement emerges through the dynamic interplay of CSR as an intervention, creating positive results using the theoretical framework of SDT and resulting in a perceived sustained state of employee engagement.

scholarly journals Preliminary Validation of a Continuum Model for Dimple Patterns on Polyethylene Naphthalate via Ar Ion Beam Sputtering

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1932
Author(s):  
Jun-Yeong Yang ◽  
Sunghoon Jung ◽  
Eun-Yeon Byeon ◽  
Hyun Hwi Lee ◽  
Do-Geun Kim ◽  
...  
Keyword(s):  
Continuum Model ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Surface Instability ◽  
The Self ◽  
Self Organization ◽  
Ion Beam Sputtering ◽  
Polyethylene Naphthalate ◽  
Preliminary Validation ◽  
Beam Sputtering

This work reports the self-organization of dimple nanostructures on a polyethylene naphthalate (PEN) surface where an Ar ion beam was irradiated at an ion energy of 600 eV. The peak-to-peak roughness and diameter of dimple nanostructures were 29.1~53.4 nm and 63.4~77.6 nm, respectively. The electron energy loss spectrum at the peaks and troughs of dimples showed similar C=C, C=O, and O=CH bonding statuses. In addition, wide-angle X-ray scattering showed that Ar ion beam irradiation did not induce crystallization of the PEN surface. That meant that the self-organization on the PEN surface could be due to the ion-induced surface instability of the amorphous layer and not due to the partial crystallinity differences of the peaks and valleys. A nonlinear continuum model described surface instability due to Ar ion-induced sputtering. The Kuramoto–Sivashinsky model reproduced the dimple morphologies numerically, which was similar to the experimentally observed dimple patterns. This preliminary validation showed the possibility that the continuum equation used for metal and semiconductor surfaces could be applied to polymer surfaces where ion beam sputtering occurred.

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