BEHAVIORAL DYNAMICS OF TWO INTERACTING HAWK–DOVE POPULATIONS

2001 ◽  
Vol 11 (04) ◽  
pp. 645-661 ◽  
Author(s):  
PIERRE AUGER ◽  
RAFAEL BRAVO DE LA PARRA ◽  
EVA SÁNCHEZ
Keyword(s):  
General Model ◽  
The Other ◽  
Phase Portraits ◽  
Behavioral Dynamics ◽  
Interacting Populations ◽  
Different Populations ◽  
The Stability ◽  
Individual Strategies ◽  
Parameter Values ◽  
Two Populations

We present a model of two interacting populations using two individual strategies, hawk and dove. Individuals encounter each other frequently and can change tactics several times in their life. Conflicts occur between individuals belonging to the same population and to different populations. The general model is based on the replicator equations which are used to describe the variations of the hawk proportions of the two populations. According to parameter values, namely the gain-, the intra- and inter-population costs, and the relative intra-population encounter rates, we classify the different phase portraits. We show that a decrease in the intra-population cost of a population provokes an increase in the hawk proportion in this population and of the dove proportion in the other population. An increase in the inter-population cost favors hawk strategy in the population which causes more injuries and dove strategy in the other. We also study the effects of the relative densities of the two populations on the stability of equilibria. In most cases, an increase in the relative density of a population leads to a decrease in hawk proportion in this population and of dove proportion in the other.

scholarly journals Stability, Bifurcation, Chaos : Discrete Prey Predator Model with Step Size

2019 ◽  
Vol 9 (1) ◽  
pp. 3382-3387 ◽  
Keyword(s):  
Chaotic Behavior ◽  
Initial Conditions ◽  
Equilibrium States ◽  
Phase Portraits ◽  
Step Size ◽  
Dynamical Nature ◽  
Predator Model ◽  
The Stability ◽  
Parameter Values ◽  
Bifurcation Chaos

In this work titled Stability, Bifurcation, Chaos: Discrete prey predator model with step size, by Forward Euler Scheme method the discrete form is obtained. Equilibrium states are calculated and the stability of the equilibrium states and dynamical nature of the model are examined in the closed first quadrant 2 R with the help of variation matrix. It is observed that the system is sensitive to the initial conditions and also to parameter values. The dynamical nature of the model is investigated with the assistance of Lyapunov Exponent, bifurcation diagrams, phase portraits and chaotic behavior of the system is identified. Numerical simulations validate the theoretical observations.

scholarly journals Chiral polymerization and the RNA world

2005 ◽  
Vol 4 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Jonathan A.D. Wattis ◽  
Peter V. Coveney
Keyword(s):  
Mathematical Models ◽  
Rna World ◽  
Steady States ◽  
Information Storage ◽  
The Other ◽  
Symmetric System ◽  
Chemical Mechanisms ◽  
Similarities And Differences ◽  
The Stability ◽  
Parameter Values

The purpose of this paper is to review two mathematical models: one for the formation of homochiral polymers from an originally chirally symmetric system; and the other, to show how, in an RNA-world scenario, RNA can simultaneously act both as information storage and a catalyst for its own production. We note the similarities and differences in chemical mechanisms present in the systems. We review these two systems, analysing steady states, interesting kinetics and the stability of symmetric solutions. In both systems we show that there are ranges of parameter values where some chains increase their own concentrations faster than others.

A Two-Patch Predator-Prey Metapopulation Model

2012 ◽  
Vol 2 (3) ◽  
pp. 238-265 ◽  
Author(s):  
G. Quaglia ◽  
E. Re ◽  
M. Rinaldi ◽  
E. Venturino
Keyword(s):  
Minimal Model ◽  
The Other ◽  
Metapopulation Model ◽  
Directional Migration ◽  
Predator Prey ◽  
First Case ◽  
Interacting Populations ◽  
Prey Interaction ◽  
Stable Equilibria ◽  
Two Populations

AbstractA minimal model for predator-prey interaction in a composite environment is presented and analysed. We first consider free migrations between two patches for both interacting populations, and then the particular cases where only one-directional migration is allowed and where only one of the two populations can migrate. Our findings indicate that in all cases the ecosystem can never disappear entirely, under the model assumptions. The predator-free equilibrium and the coexistence of all populations are found to be the only feasible stable equilibria. When there are only one-directional migrations, the abandoned patch cannot be repopulated. Other equilibria then arise, with only prey in the second patch, coexistence in the second patch, or prey in both patches but predators only in the second one. For the case of sedentary prey, with predator migration, the prey cannot thrive alone in either of the two environments. However, predators can survive in a prey-free patch due to their ability to migrate into the other patch, provided prey is present there. If only the prey can migrate, the predators may be eliminated from one patch or from both. In the first case, the patch where there are no predators acts as a refuge for the survival of the prey.

scholarly journals Morphometric comparison between two populations of Aonidiella aurantii (Maskell) (Homoptera: Diaspididae) from Algeria and Turkey

2020 ◽  
Vol 10 (5) ◽  
pp. 240-244
Author(s):  
K. Boudjemaa ◽  
I. Karaca ◽  
M. Biche
Keyword(s):  
Size Variation ◽  
The Other ◽  
Host Quality ◽  
Parasitism Rate ◽  
Aonidiella Aurantii ◽  
Aphytis Melinus ◽  
Climatic Variations ◽  
Scale Population ◽  
Different Populations ◽  
Two Populations

The size of California red scale Aonidiella aurantii (Maskell, 1879) (Homoptera: Diaspididae) is the most reliable indicator in terms of host quality for Aphytis melinus (DeBach, 1959) (Hymenoptera: Aphelinidae) as well as for the efficiency of its biological control. Our study consisted in comparing the cover and body size of each scale developmental stage belonging to two different populations: one from Algeria and the other one from Turkey. The two scale populations were taken from lemon trees during 3 months. We compared measurements between the two localities and also between the plant organs. The larger individuals were those from Algeria. The same results were confirmed through the plant substrate on which scale was fixed: this size variation observed is mainly explained by climatic variations between the two countries and its repercussions on phenology and metabolism of the host plant. In addition, a higher parasitism rate was noticed in the Algerian scale population compared to that of Turkey.

CHAOS IN A THREE-DIMENSIONAL GENERAL MODEL OF NEURAL NETWORK

2002 ◽  
Vol 12 (10) ◽  
pp. 2271-2281 ◽  
Author(s):  
A. DAS ◽  
PRITHA DAS ◽  
A. B. ROY
Keyword(s):  
Neural Network ◽  
Differential Equations ◽  
General Model ◽  
Three Dimensional ◽  
Stationary Regime ◽  
Decay Rates ◽  
Phase Portraits ◽  
Study Phase ◽  
Bifurcation Diagrams ◽  
Parameter Values

The dynamics of a network of three neurons with all possible connections is studied here. The equations of control are given by three differential equations with nonlinear, positive and bounded sigmoidal response function of the neurons. The system passes from stable to periodic and then to chaotic regimes and returns to stationary regime with change in parameter values of synaptic weights and decay rates. We have developed programs and used Locbif package to study phase portraits, bifurcation diagrams which confirm the result. Lyapunov Exponents have been calculated to confirm chaos.

scholarly journals Synchronization in ensembles of coupled maps with a major element

2005 ◽  
Vol 2005 (3) ◽  
pp. 239-255 ◽  
Author(s):  
Iryna Omelchenko ◽  
Yuri Maistrenko ◽  
Erik Mosekilde
Keyword(s):  
Chaotic Maps ◽  
Major Element ◽  
The Other ◽  
Parameter Mismatch ◽  
Partial Synchronization ◽  
One Dimensional ◽  
Coupled Maps ◽  
One Dimensional Maps ◽  
Parameter Values ◽  
Two Populations

The paper investigates the conditions for full and partial synchronization in systems of coupled chaotic maps that include the presence of a major element, that is, an element that interacts with all the other elements of the system. We consider a system which consists of two globally coupled populations of one-dimensional maps that interact via a major element. The presence of this element can induce synchronization in both of the globally coupled populations even though they operate in different states. If a parameter mismatch is introduced between two populations of uncoupled maps, the presence of a major element is found to provide for the existence of states in which peripheral elements with different parameter values display similar dynamics.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

scholarly journals Black Hole Algorithm for Sustainable Design of Counterfort Retaining Walls

2020 ◽  
Vol 12 (7) ◽  
pp. 2767 ◽  
Author(s):  
Víctor Yepes ◽  
José V. Martí ◽  
José García
Keyword(s):  
Black Hole ◽  
Sustainable Design ◽  
Retaining Walls ◽  
The Other ◽  
Trade Off ◽  
Construction Company ◽  
Geometric Variables ◽  
The Stability ◽  
The Cost ◽  
Black Hole Algorithm

The optimization of the cost and CO 2 emissions in earth-retaining walls is of relevance, since these structures are often used in civil engineering. The optimization of costs is essential for the competitiveness of the construction company, and the optimization of emissions is relevant in the environmental impact of construction. To address the optimization, black hole metaheuristics were used, along with a discretization mechanism based on min–max normalization. The stability of the algorithm was evaluated with respect to the solutions obtained; the steel and concrete values obtained in both optimizations were analyzed. Additionally, the geometric variables of the structure were compared. Finally, the results obtained were compared with another algorithm that solved the problem. The results show that there is a trade-off between the use of steel and concrete. The solutions that minimize CO 2 emissions prefer the use of concrete instead of those that optimize the cost. On the other hand, when comparing the geometric variables, it is seen that most remain similar in both optimizations except for the distance between buttresses. When comparing with another algorithm, the results show a good performance in optimization using the black hole algorithm.

scholarly journals A Fractional SAIDR Model in the Frame of Atangana–Baleanu Derivative

2021 ◽  
Vol 5 (2) ◽  
pp. 32
Author(s):  
Esmehan Uçar ◽  
Sümeyra Uçar ◽  
Fırat Evirgen ◽  
Necati Özdemir
Keyword(s):  
Existence And Uniqueness ◽  
Laplace Transformation ◽  
Cell Phones ◽  
Mobile Network ◽  
The Other ◽  
Banach Fixed Point Theorem ◽  
Propagation Models ◽  
Computer Worms ◽  
Computer Viruses ◽  
The Stability

It is possible to produce mobile phone worms, which are computer viruses with the ability to command the running of cell phones by taking advantage of their flaws, to be transmitted from one device to the other with increasing numbers. In our day, one of the services to gain currency for circulating these malignant worms is SMS. The distinctions of computers from mobile devices render the existing propagation models of computer worms unable to start operating instantaneously in the mobile network, and this is particularly valid for the SMS framework. The susceptible–affected–infectious–suspended–recovered model with a classical derivative (abbreviated as SAIDR) was coined by Xiao et al., (2017) in order to correctly estimate the spread of worms by means of SMS. This study is the first to implement an Atangana–Baleanu (AB) derivative in association with the fractional SAIDR model, depending upon the SAIDR model. The existence and uniqueness of the drinking model solutions together with the stability analysis are shown through the Banach fixed point theorem. The special solution of the model is investigated using the Laplace transformation and then we present a set of numeric graphics by varying the fractional-order θ with the intention of showing the effectiveness of the fractional derivative.

scholarly journals Competing Conventions with Costly Information Acquisition

Games ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 53
Author(s):  
Roberto Rozzi
Keyword(s):  
Information Acquisition ◽  
Evolutionary Model ◽  
Equilibrium Selection ◽  
The Other ◽  
Group Interactions ◽  
Social Coordination ◽  
Long Run ◽  
Stochastic Stability Analysis ◽  
The Stability ◽  
The Cost

We consider an evolutionary model of social coordination in a 2 × 2 game where two groups of players prefer to coordinate on different actions. Players can pay a cost to learn their opponent’s group: if they pay it, they can condition their actions concerning the groups. We assess the stability of outcomes in the long run using stochastic stability analysis. We find that three elements matter for the equilibrium selection: the group size, the strength of preferences, and the information’s cost. If the cost is too high, players never learn the group of their opponents in the long run. If one group is stronger in preferences for its favorite action than the other, or its size is sufficiently large compared to the other group, every player plays that group’s favorite action. If both groups are strong enough in preferences, or if none of the groups’ sizes is large enough, players play their favorite actions and miscoordinate in inter-group interactions. Lower levels of the cost favor coordination. Indeed, when the cost is low, in inside-group interactions, players always coordinate on their favorite action, while in inter-group interactions, they coordinate on the favorite action of the group that is stronger in preferences or large enough.

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