3+4+Supplementum/2012 - Společnost pro pojivové tkáně

change their states and structure in the
finite time points, for example the software
GPSS which is used for economic
and administrative tasks.
3. Combined discrete continuous simulation
makes possible to compare model
witch change their states continuous in
time and its structure in the finite time
points, for example software CDCSIS,
which will be used in this article.
Combined simulation makes possible
to compare continuous and discrete
models too. The combined simulation
is used for solving of differential equations
witch change their structure in
time.
The software CDCSIS is assembled as
library of procedures at language C++.
A simulation model in language C++ is
compiled as set of discrete, continuous and
check blocks:
z discrete block makes disposable calculations
at specific situations,
z continuous block makes particular calculation
under certain situation, for
example calculation of right side of
differential equation,
z check block watches ever the model
structure could have be changed.
A calling of the library procedures
schedules calculation according to the
block and/or finishing of the calculation
according to the block, starting and/or
finishing of integration, graph output and
animation.
The top of article is not to learn any
software and/or get to know a simulation
using at some branch but to show a simulation
advantage and simplicity on 3 examples
and makes a propagation of this scientific
method. The continuous simulation
will be performed on the model of grippe
infection (eventually the other infect
illness). The discrete simulation will be
shown on hospital beds exploitation. The
combined simulation will be performed on
the model of spine bending under orthesis
loading. The algorithms will be described
by calculation diagrams. The scheduling of
calculation according to block is provided
by the procedure “schedule(starting time,
calling block, continuous or discrete block,
parameters)”. The procedure „cancelblock(canceled
block)“ finishes calculation
according to continuous block and the procedure
„integr(vector length, integrated
vector, output vector, integration name)“
starts integration and the procedure „cancelint(integration
name)“ the integration
finishes.
Grippe infection model
The first example is continuous simulation,
it means the structure model is fixed
and the signals are changed continuous
in time. The infection is simulated at closed
community with n persons. The time
unit is coincident with illness time include
incubation period. Each person after grippe
illness is resistant.
Let’s designate:
n number of persons at community
State number of persons endangered by
grippe
Infect number of infected persons
The velocity change of number of persons
endangered by grippe (derivation) is
proportional to their number and number
of infected persons, in mathematic formulation:
State´ = -r.State.Infect, (1)
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