Simulation Based Analysis of Nanocarrier Internalization: Exciting Challenges with a New Computational Tool - Intracellular Delivery: Fundamentals and Applications - page 135

p 1 p 2

p 3 p 4

INP
PROG
(m)
OUT

INP
PROG
(m)
OUT

INP
PROG
(m)
OUT

INP
PROG
(m)
OUT

State (measures,
singns)

P

Modifying
channels

Reading
channels

x

y y

Transitions (transportations,
transformations, rules)

INP
PROG
(v)
OUT

INP
PROG (v)
OUT

INP
PROG (v)
OUT

A

a 1

a 3

a 2

Fig. 3 General architecture of the process models in sense of direct computer mapping

The discrete or continuous and the quantitative or qualitative functioning of the
structural modules can be determined by the expert-defined brief programs (m or v).
The passive output → active input and the active output → passive input connections
are described by the reading (X) and modifying (Y) connections, respectively.
Considering our example model, we describe “passive” state elements for the com-
ponents in the compartments, as well as “active” transition elements for the trans-
portations and transformations summarized in Table 1 . The calculations are
described by the brief programs, associated with these elements, represented by
boxes. The various edges (lines) correspond to the information flow between the
elements. Accordingly the system determines and makes possible the execution of a
dynamic model without the usual mathematical formalisms and without any special
numerical solver (that is embedded in the general kernel, see in Fig. 4 ).
The method can be applied for the computer modeling, dynamic simulation and
simulation based problem solving of various process systems (Csukas et al. 1999,
2000 ; Nagy et al. 2001 ; Temesvari et al. 2004 ; Varga et al. 2010 ).
The schematic architecture of the computer implementation is illustrated in
Fig. 4 . The brief programs determine the calculation of the active (v) and passive
(m) functionalities. The respective expressions are declared by the expert. The
structure and the parameters of the actual problem are described by the user.
The execution consists of four cyclically repeated consecutive steps, as
follows:

1. active elements read the content of the associated passive elements through to
the reading channels;
2. brief programs, associated with active elements calculate the changes;
3. passive elements are modified according to the changes carried via modifying
channels;
4. brief programs, associated with passive elements calculate the new state.