NIP REPORT January 2006- May 2007 - The UP College of Science ...

Title: Complexity in Competitive Populations
Duration: January to December 2006
Amount: PhP 36,000.00
i. Dr. Cristine Villagonzalo
Title: Modeling of TwoDimensional Electron Gases' Thermodynamics
Properties in the Fractional Quantum Hall Regime
Duration: January to December 2006
Amount: PhP 36,000.00
Part II. Summary of Past and Ongoing Research Projects
The physics of macroscopic and microscopic systems from bulk solids and living organisms to atoms and
molecules are dictated by their structure and the dynamics of their constituent parts. Understanding these
underlying principles through theoretical and computational methods is the
research thrust of the Structure and Dynamics Group.
I. Theoretical and Computational Physics
A. Penna Model [Dr. Banzon]
We started investigations on a population dynamics model that yields a Gompertzian age
structure distribution -
the Penna Model. It is a model that conforms to the mutation accumulation theory of aging. We s
howed that a Penna bitstring model with only 8bits
exhibits the same chaotic properties as that of the original 32bit model.[Nombres]
A variant implementation of the model was also investigated that which applied the so
called Verhulst factor (to account for the influence of the environmental carrying capacity)
only to newborns (VB), as opposed to all ages in the original model. This implementation
takes into account the idea that older individuals are able to adapt to the environment. It was
found that it displays a greater degree of chaos compared to the original (VA)
implementation. Also, the effective carrying capacity is explicitly defined only for the age at
which the Verhulst factor is applied.[Nombres, Beech]
It was noted that the newer, biologically more acceptable implementation (VB) does not
yield a Gompertzian age structure. The nonGompertzian distribution was accounted for by
an observed time dependence of the distribution with a shortterm periodicity. [Beech]
Intraspecific competition was simulated for different Penna parameters. It was found that in
general, the preferred population exhibits less fluctuation in its timeseries. [Beech]
The degree of complexity associated with the resulting timeseries for a population was
estimated using the embedding dimension. [Mandingiado, Ibo]
A study was made to find a correlation between the embedding dimension and the
competitiveness of a population. [Mandingiado]
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