Psycho-Cognitive Aspects of Dynamic Model-Building in Logo: A Simple Population Evolution and Predator/Prey Program

1988 ◽  
Vol 4 (3) ◽  
pp. 227-252 ◽  
Author(s):  
Bruno Vitale
Keyword(s):  
Dynamical Systems ◽  
Dynamic Model ◽  
Model Building ◽  
Mutual Interaction ◽  
Dynamical Models ◽  
Single Population ◽  
Predator Prey ◽  
Population Evolution ◽  
Programming Skills ◽  
Two Populations

A family of simple models, which can be deployed from the case of the growth of a single population to the mutual interaction of two populations in a predators/prey relation, is programmed in LOGO by using the most elementary programming skills. The deployment is followed step by step, by emphasizing the elements of cognitive novelty and the possible cognitive obstructions, more than the possible programming difficulties. This family of models is used to model a way of introducing, through programming experience, dynamical models of change and a first approach to dynamical systems.

Coevolutionary Computation

1995 ◽  
Vol 2 (4) ◽  
pp. 355-375 ◽  
Author(s):  
Jan Paredis
Keyword(s):  
Neural Net ◽  
Noise Tolerance ◽  
Biologically Inspired ◽  
Single Population ◽  
Genetic Search ◽  
Predator Prey ◽  
Fitness Evaluation ◽  
Different Types ◽  
Coevolutionary Computation ◽  
Two Populations

This article proposes a general framework for the use of coevolution to boost the performance of genetic search. It combines coevolution with yet another biologically inspired technique, called lifetime fitness evaluation (LTFE). Two unrelated problems—neural net learning and constraint satisfaction—are used to illustrate the approach. Both problems use predator-prey interactions to boost the search. In contrast with traditional “single population” genetic algorithms (GAs), two populations constantly interact and coevolve. However, the same algorithm can also be used with different types of coevolutionary interactions. As an example, the symbiotic coevolution of solutions and genetic representations is shown to provide an elegant solution to the problem of finding a suitable genetic representation. The approach presented here greatly profits from the partial and continuous nature of LTFE. Noise tolerance is one advantage. Even more important, LTFE is ideally suited to deal with coupled fitness landscapes typical for coevolution.

scholarly journals Dynamic model updating (DMU) approach for statistical learning model building with missing data

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Rahi Jain ◽  
Wei Xu
Keyword(s):  
Missing Data ◽  
Dynamic Model ◽  
Statistical Models ◽  
Missing Values ◽  
Model Building ◽  
Model Updating ◽  
Biological Data ◽  
Bayesian Regression ◽  
Biological Research ◽  
Original Dataset

Abstract Background Developing statistical and machine learning methods on studies with missing information is a ubiquitous challenge in real-world biological research. The strategy in literature relies on either removing the samples with missing values like complete case analysis (CCA) or imputing the information in the samples with missing values like predictive mean matching (PMM) such as MICE. Some limitations of these strategies are information loss and closeness of the imputed values with the missing values. Further, in scenarios with piecemeal medical data, these strategies have to wait to complete the data collection process to provide a complete dataset for statistical models. Method and results This study proposes a dynamic model updating (DMU) approach, a different strategy to develop statistical models with missing data. DMU uses only the information available in the dataset to prepare the statistical models. DMU segments the original dataset into small complete datasets. The study uses hierarchical clustering to segment the original dataset into small complete datasets followed by Bayesian regression on each of the small complete datasets. Predictor estimates are updated using the posterior estimates from each dataset. The performance of DMU is evaluated by using both simulated data and real studies and show better results or at par with other approaches like CCA and PMM. Conclusion DMU approach provides an alternative to the existing approaches of information elimination and imputation in processing the datasets with missing values. While the study applied the approach for continuous cross-sectional data, the approach can be applied to longitudinal, categorical and time-to-event biological data.

scholarly journals Coexistence and Noncoexistence of Markovian Viruses and their Hosts

2014 ◽  
Vol 51 (1) ◽  
pp. 191-208 ◽  
Author(s):  
Jakob E. Björnberg ◽  
Erik I. Broman
Keyword(s):  
Virus Infection ◽  
Predator Prey ◽  
Classic Problem ◽  
Infected Cells ◽  
Predator Prey Models ◽  
Two Populations ◽  
Competing Populations

Examining possibilities for the coexistence of two competing populations is a classic problem which dates back to the earliest ‘predator-prey’ models. In this paper we study this problem in the context of a model introduced in Björnberg et al. (2012) for the spread of a virus infection in a population of healthy cells. The infected cells may be seen as a population of ‘predators’ and the healthy cells as a population of ‘prey’. We show that, depending on the parameters defining the model, there may or may not be coexistence of the two populations, and we give precise criteria for this.

Extinction probabilities in predator–prey models

1986 ◽  
Vol 23 (01) ◽  
pp. 1-13
Author(s):  
S. E. Hitchcock
Keyword(s):  
Stochastic Models ◽  
Birth Rate ◽  
Exact Expression ◽  
Initial Population ◽  
Predator Prey ◽  
Extinction Probabilities ◽  
Population Sizes ◽  
The Mean ◽  
Predator Prey Models ◽  
Two Populations

Two stochastic models are developed for the predator-prey process. In each case it is shown that ultimate extinction of one of the two populations is certain to occur in finite time. For each model an exact expression is derived for the probability that the predators eventually become extinct when the prey birth rate is 0. These probabilities are used to derive power series approximations to extinction probabilities when the prey birth rate is not 0. On comparison with values obtained by numerical analysis the approximations are shown to be very satisfactory when initial population sizes and prey birth rate are all small. An approximation to the mean number of changes before extinction occurs is also obtained for one of the models.

Intrinsic and measured statistics of discrete stochastic populations

2008 ◽  
Vol 464 (2099) ◽  
pp. 2929-2948 ◽  
Author(s):  
O.E French ◽  
K.I Hopcraft ◽  
E Jakeman ◽  
T.J Shepherd
Keyword(s):  
Measurement Technique ◽  
Statistical Properties ◽  
Single Population ◽  
Quantum Phenomena ◽  
Two Populations

The notion that the nature of a measurement is critical to its outcome is usually associated with quantum phenomena. In this paper, we show that the observed statistical properties are also a function of the measurement technique in the case of simple classical populations. In particular, the measured and intrinsic statistics of a single population may be different, while correlation and transfer of individuals between two populations may be hidden from the observer.

scholarly journals Coexistence and Noncoexistence of Markovian Viruses and their Hosts

2014 ◽  
Vol 51 (01) ◽  
pp. 191-208 ◽  
Author(s):  
Jakob E. Björnberg ◽  
Erik I. Broman
Keyword(s):  
Virus Infection ◽  
Predator Prey ◽  
Classic Problem ◽  
Infected Cells ◽  
Predator Prey Models ◽  
Two Populations ◽  
Competing Populations

Examining possibilities for the coexistence of two competing populations is a classic problem which dates back to the earliest ‘predator-prey’ models. In this paper we study this problem in the context of a model introduced in Björnberg et al. (2012) for the spread of a virus infection in a population of healthy cells. The infected cells may be seen as a population of ‘predators’ and the healthy cells as a population of ‘prey’. We show that, depending on the parameters defining the model, there may or may not be coexistence of the two populations, and we give precise criteria for this.

scholarly journals Dynamical Models of Interactions between Herds Forage and Water Resources in Sahelian Region

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Jean Jules Tewa ◽  
Alassane Bah ◽  
Suares Clovis Oukouomi Noutchie
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Mathematical Models ◽  
Optimal Foraging ◽  
Consumer Behaviour ◽  
High Variability ◽  
Dynamical Models ◽  
Predator Prey ◽  
Abrupt Changes ◽  
Predator Prey Models

Optimal foraging is one of the capital topics nowadays in Sahelian region. The vast majority of feed consumed by ruminants in Sahelian region is still formed by natural pastures. Pastoral constraints are the high variability of available forage and drinking water in space and especially in time (highly seasonal, interannual variability) and the scarcity of water resources. The mobility is the main functional and opportunistic adaptation to these constraints. Our goal in this paper is to formalize two dynamical models for interactions between a herd of domesticate animals, forage resources, and water resources inside a given Sahelian area, in order to confirm, explain, and predict by mathematical models some observations about pastoralism in Sahelian region. These models in some contexts can be similar to predator-prey models as forage and water resources can be considered as preys and herd’s animals as predators. These models exhibit very rich dynamics, since it predicts abrupt changes in consumer behaviour and disponibility of forage or water resources. The dynamics exhibits a possible coexistence between herd, resources, and water with alternative peaks in their trajectories.

A European warm waters neophyte Shinnersia rivularis — new alien species to the Slovak flora

Biologia ◽  
2009 ◽  
Vol 64 (4) ◽  
Author(s):  
Pavol Eliáš ◽  
Michal Hájek ◽  
Petra Hájková
Keyword(s):  
Alien Species ◽  
Central Europe ◽  
Water Surface ◽  
Thermal Spring ◽  
Warm Water ◽  
Single Population ◽  
A Site ◽  
Two Populations

AbstractShinnersia rivularis is reported as a new alien species of the Slovak flora. The species was found in the catchment water of a thermal spring at a site in Partizánske, part Veľké Bielice (West Slovakia) in 2002. In the year of discovery, plants formed single population of about 30 square metres of water surface of the canal discharging warm water from the spa. Two populations covering the area ca 90 square meters were found in 2007. A brief description of the species is given and its distribution in Central Europe is reviewed. So far, the species has been reported from only three localities in Central Europe, which are distributed in three countries: Austria, Hungary and Germany.

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