Details

Autor(en) / Beteiligte

• Luckyanov, N.K.
• Svirezhev, Yu.M.
• Voronkova, O.V.

Titel

Aggregation of variables in simulation models of water ecosystems

Ist Teil von

• Ecological modelling, 1983-01, Vol.18 (3), p.235-240

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

1983

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• The problem of variable aggregation in simulation model is considered. By aggregation is understood the unification of some variables of the system which are related to one another, into some sort of blocks each of which is a new variable with the properties defined by the aggregation laws. Let us take such a model, described by a system of differential equations with the set of variables { X i } ( i = 1,…, N). The problem is tofind a set of variables { Y j } ( j=1,…, M; M⩽ N) that is related to the set { X i } by equations Y= φ j ( X) such that the new system of differential equations can be described by variables { Y i } only. it brings us to the problem of the representability of a function of many variables { X i } in the aggregated variables { Y j }. Two criteria of representability are given. The withthe help of these criteria, the criterion of aggregation for some general model of a two-level ecological system is deduced.