Team:KULeuven/Modelling

From 2009.igem.org

(Difference between revisions)
(Step 1 and 2: Modelling and simulation)
(Introduction)
Line 11: Line 11:
* the role of ordinary differential equations
* the role of ordinary differential equations
* modelling applied to iGEM
* modelling applied to iGEM
-
this presentations is mainly based on the presentation of last year and the wiki of ETH Zürich 2007.
+
this presentation is mainly based on the presentation of last year and the wiki of ETH Zürich 2007.
== Modelling overview ==
== Modelling overview ==

Revision as of 11:10, 30 July 2009


Introduction

As an introduction to modelling we made a short presentation. This presentation handles about the following:

  • some definitions and the role of modelling
  • black and white box modelling
  • the role of ordinary differential equations
  • modelling applied to iGEM

this presentation is mainly based on the presentation of last year and the wiki of ETH Zürich 2007.

Modelling overview

Controller system.png

The scientific procedure for the study of a physical system can be divided in the following 3 steps

  • Parameterization of the system: discover the minimal set of parameters that completely define the system.
  • Foward modelling: define the physical laws that, given the values of the parameters of the system, determine the value of the observable parameters.
  • Inverse modelling: given observed parameters, infer the actual parameters that produced the observed data.

Most of the time this is an iterative approach, the last step will contain an indication of how good the model fits the observed data. Sometimes it will be necessary to adjust the proposed model, if it doesn't fit the observed data.

Step 1 and 2: Modelling and simulation

For0026l.jpg

By a model, we mean an abstraction of some real system that can be used to obtain predictions and formulate control strategies. In order to be useful, a model must necessarily incorporate elements of two conflicting attributes:

  • realism
  • simplicity

One the one hand, the model should serve as a reasonably close approximation to the real system, on the other hand, the model must not be overly complex so as to preclude its understanding and manipulation. All that's required is a high correlation between predictions and real-life performance.

Step 3: Inverse modelling

While the first two steps are mainly deductive, the third step is inductive. The inverse problem consists of using the actual result of some measurements to infer the value of the parameters that characterize the system.

While the forward problem has (in deterministic physics) a unique solution, the inverse problem does not. The most general theory is obtained when using a probabilistic point of view, where the a priori information on the model parameters is represented by a probability distribution over the 'model space'.

Kinetic constants

Dilbert param.strip.gif

References

["Inverse problem theory and methods for model parameter estimation", Albert Tarantola]
["Modern simulation and modeling", Reuven Y. Rubinstein, Benjamin Melamed]