An agent-based collaborative evolutionary model for multimodal optimization

2008 ◽  
Author(s):  
Rodica I. Lung ◽  
Camelia Chira ◽  
D. Dumitrescu
Keyword(s):  
Evolutionary Model ◽  
Multimodal Optimization ◽  
Agent Based

scholarly journals Modeling long lifespans in eusocial insect populations

2018 ◽  
Author(s):  
Donepudi RaviTeja ◽  
Ramakrishna Ramaswamy
Keyword(s):  
Evolutionary Model ◽  
Dominant Strategy ◽  
Division Of Labour ◽  
Agent Based ◽  
Eusocial Insect ◽  
Extrinsic Mortality ◽  
Extended Lifespan ◽  
Evolution Of Eusociality ◽  
Eusocial Species ◽  
Migration Probability

AbstractAlong with division of labour, and life-history complexities, a characteristic of eusocial insect societies is the greatly extended lifespan for queens. The colony structure reduces the extrinsic mortality of the queen, and according to classical evolutionary theories of ageing, this greatly increases the lifespan. We explore the relationship between the evolution of longevity and the evolution of eusociality by introducing age-structure into a previously proposed evolutionary model and also define an associated agent-based model. A set of three population structures are defined: (i) solitary with all reproductive individuals, (ii) monogynous eusocial with a single queen, and (iii) polygynous eusocial, with multiple queens.In order to compare the relative fitnesses we compete all possible pairs of these strategies as well as all three together, analysing the effects of parameters such as the probability of progeny migration, group benefits, and extrinsic mortality on the evolution of long lifespans. Simulations suggest that long lifespans appear to evolve only in eusocial populations, and further, that long lifespans enlarge the region of parameter space where eusociality evolves. When all three population strategies compete, the agent-based simulations indicate that solitary strategies are largely confined to shorter lifespans. For long lifespan strategies the solitary behaviour results only for extreme (very low or very high) migration probability. For median and small values of migration probability, the polygynous eusocial and monogynous eusocial strategies give advantage to the population respectively. For a given migration probability, with an increase in lifespan, the dominant strategy changes from solitary to polygynous to monogynous eusociality. The evolution of a long lifespan is thus closely linked to the evolution of eusociality, and our results are in accord with the observation that the breeding female in monogynous eusocial species has a longer lifespan than those in solitary or polygynous eusocial species.

scholarly journals Inferring mechanisms of response prioritization on social media under information overload

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chathika Gunaratne ◽  
William Rand ◽  
Ivan Garibay
Keyword(s):  
Social Media ◽  
Information Overload ◽  
User Interaction ◽  
Evolutionary Model ◽  
Online Information ◽  
Information Cascades ◽  
Agent Based Model ◽  
Agent Based ◽  
Highly Active ◽  
Online Social Media

AbstractHuman decision-making is subject to the biological limits of cognition. The fluidity of information propagation over online social media often leads users to experience information overload. This in turn affects which information received by users are processed and gain a response to, imposing constraints on volumes of, and participation in, information cascades. In this study, we investigate properties contributing to the visibility of online social media notifications by highly active users experiencing information overload via cross-platform social influence. We analyze simulations of a coupled agent-based model of information overload and the multi-action cascade model of conversation with evolutionary model discovery. Evolutionary model discovery automates mechanistic inference on agent-based models by enabling random forest importance analysis on genetically programmed agent-based model rules. The mechanisms of information overload have shown to contribute to a multitude of global properties of online information cascades. We investigate nine characteristics of online messages that may contribute to the prioritization of messages for response. Our results indicate that recency had the largest contribution to message visibility, with individuals prioritizing more recent notifications. Global popularity of the conversation originator had the second highest contribution, and reduced message visibility. Messages that presented opportunity for novel user interaction, yet high reciprocity showed to have relatively moderate contribution to message visibility. Finally, insights from the evolutionary model discovery results helped inform response prioritization rules, which improved the robustness and accuracy of the model of information overload.

MODEL OF INFLUENCE: FROM INDIVIDUAL DECISIONS TO LOCKED-IN MARKETS

2006 ◽  
Vol 09 (01n02) ◽  
pp. 59-67
Author(s):  
SEBASTIAN D. GUALA
Keyword(s):  
Initial Conditions ◽  
Evolutionary Model ◽  
Numerical Results ◽  
Square Lattice ◽  
Agent Based ◽  
Individual Decisions ◽  
Lock In

We introduce an agent-based, evolutionary model of decisions inspired by the increasing return theory. Agents have to choose between options taking into account their own preferences and externalities from their neighbors. The aim is to analyze the distribution of decisions in a square lattice domain and its dependence on the initial conditions. Numerical results show that an undesirable option may be adopted by the majority and may lock in markets by means of clever or lucky movements done at the beginning.

scholarly journals Multiple phase transitions in an agent-based evolutionary model with neutral fitness

2017 ◽  
Vol 4 (4) ◽  
pp. 170005 ◽  
Author(s):  
Dawn M. King ◽  
Adam D. Scott ◽  
Sonya Bahar
Keyword(s):  
Fossil Record ◽  
Fitness Landscape ◽  
Phenotypic Diversity ◽  
Null Model ◽  
Evolutionary Model ◽  
Reaction Diffusion ◽  
Universality Class ◽  
Neutral Evolution ◽  
Agent Based ◽  
Phenotype Space

Null models are crucial for understanding evolutionary processes such as speciation and adaptive radiation. We analyse an agent-based null model, considering a case without selection—neutral evolution—in which organisms are defined only by phenotype. Universal dynamics has previously been demonstrated in a related model on a neutral fitness landscape, showing that this system belongs to the directed percolation (DP) universality class. The traditional null condition of neutral fitness (where fitness is defined as the number of offspring each organism produces) is extended here to include equal probability of death among organisms. We identify two types of phase transition: (i) a non-equilibrium DP transition through generational time (i.e. survival), and (ii) an equilibrium ordinary percolation transition through the phenotype space (based on links between mating organisms). Owing to the dynamical rules of the DP reaction–diffusion process, organisms can only sparsely fill the phenotype space, resulting in significant phenotypic diversity within a cluster of mating organisms. This highlights the necessity of understanding hierarchical evolutionary relationships, rather than merely developing taxonomies based on phenotypic similarity, in order to develop models that can explain phylogenetic patterns found in the fossil record or to make hypotheses for the incomplete fossil record of deep time.

Competition, training, heterogeneity persistence, and aggregate growth in a multi-agent evolutionary model

2000 ◽  
Vol 03 (01n04) ◽  
pp. 335-351 ◽  
Author(s):  
Gérard Ballot ◽  
Erol Taymaz
Keyword(s):  
Human Capital ◽  
Negative Impact ◽  
Evolutionary Model ◽  
Agent Based ◽  
Long Run ◽  
Lower Extent ◽  
Aggregate Growth ◽  
Multi Agent ◽  
General Human Capital ◽  
Better Than

We use the framework of a multi-agent based macroeconomic model to analyse the possibility in the long run of the coexistence of two alternative types of firm behaviour towards the accumulation of human capital, training and poaching, and its aggregate outcomes. Besides R&D, we assume that firms need workers endowed with general human capital (or competencies) in order to innovate but also, although to much lower extent, in order to imitate innovations. Firms can either train workers or poach trained workers. Firms are assigned a type, and experiments compare the outcomes of the change of key parameters. The main results are: i) the coexistence of trainers and poachers is possible in the long run, and can even be beneficial to the economy when poachers raid inefficient trainers, ii) trainers fare somewhat better than poachers do, iii) mobility costs have a major negative impact on aggregate performance.

Why do people believe in a zero-sum economy?

2018 ◽  
Vol 41 ◽  
Author(s):  
Samuel G. B. Johnson
Keyword(s):  
Perspective Taking ◽  
Evolutionary Model ◽  
Everyday Experience ◽  
Coalitional Psychology ◽  
The Face ◽  
Zero Sum

AbstractZero-sum thinking and aversion to trade pervade our society, yet fly in the face of everyday experience and the consensus of economists. Boyer & Petersen's (B&P's) evolutionary model invokes coalitional psychology to explain these puzzling intuitions. I raise several empirical challenges to this explanation, proposing two alternative mechanisms – intuitive mercantilism (assigning value to money rather than goods) and errors in perspective-taking.

Total etch dentin bonding systems: scanning electron microscopy of the resin-dentin hybrid layer

1992 ◽  
Vol 50 (2) ◽  
pp. 1092-1093
Author(s):  
Jorge Perdigao
Keyword(s):  
Composite Resin ◽  
Mechanical Interlocking ◽  
Hybrid Layer ◽  
Agent Based ◽  
Dentin Bonding ◽  
Acid Agent ◽  
Bond Strengths ◽  
Main Component ◽  
Bonding Systems ◽  
New Generation

In 1955, Buonocore introduced the etching of enamel with phosphoric acid. Bonding to enamel was created by mechanical interlocking of resin tags with enamel prisms. Enamel is an inert tissue whose main component is hydroxyapatite (98% by weight). Conversely, dentin is a wet living tissue crossed by tubules containing cellular extensions of the dental pulp. Dentin consists of 18% of organic material, primarily collagen. Several generations of dentin bonding systems (DBS) have been studied in the last 20 years. The dentin bond strengths associated with these DBS have been constantly lower than the enamel bond strengths. Recently, a new generation of DBS has been described. They are applied in three steps: an acid agent on enamel and dentin (total etch technique), two mixed primers and a bonding agent based on a methacrylate resin. They are supposed to bond composite resin to wet dentin through dentin organic component, forming a peculiar blended structure that is part tooth and part resin: the hybrid layer.

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