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

Each patient has the record:
name name and other patient data,
tcure cure time,
start cure start time.
Now the simulation program will be
build. The current time is denoted time.
The each data list has the record structure;
each record has a pointer to the next
record. The record is on the fix place and
its move, delay and ads are provided as
change of its pointer.
The hospital state is changed with
help block; each type change has its own
block. The patient arrival is implemented
by block1 and the patient departure makes
block2. The compute diagrams of blocks
are showed at the appendix.
The main program reads from input
monitoring time, number of hospital
departments and for each department
build up the record (see the data list of
hospital department). If the patient or
queue list is empty then the pointer is zero.
The statement schedule of block1 calls the
first patient coming. The statement wait is
a jump to simulation system. After return
from simulation are calculated percent of
bed utilizing and average queue length
from formulas:
utilizing.100/observing time;
daverage/observing time;
Spine bending
Let’s show a combined simulation
example; the continuous solving of differential
equations witch changing their
structure. Let’s determine a bend curve
w(x) of the spine axis loaded by orthesis.
The task will be solved as a 2D system at
frontal plane. Let’s suppose that it is known
function f(x) which calculates spine loading
and where x is distance from the
upper spine end. The inter-vertebrae disc
is supposed ideal elastic and the vertebrae
stiff. The differential equations according
to linear elasticity theory for the bending
moment M and spine bend curve w are:
M" = –f (x), (3)
w ''
M(
x)
−
EI
= , (4)
where E is the elasticity modulus and
I the inertia moment, it is the values which
can be determined for inter-vertebrae disc.
The lineal curve w at stiff vertebra are
given by differential equations:
w´(x) = w 0´, (5)
where w 0´ is a initial condition at the
vertebra start.
The simulation program will be written
now. The camber w and its derivation w’,
w’’ at last point is stored at the vector w,
the bending moment M, cross-sectional
force Q and loading –f(x) are stored as
vector M. The zero initial conditions of w,
w’, M, M’=Q are set at spine beginning. The
last inter-vertebrae disc values are initial
condition for next vertebra and vice versa.
The coordinate x is the distance from spine
beginning and it will be interpreted as
simulation time. The right sides of differential
equation (3), (4) calculate continuous
blocks:
block1: M[2] = –f(t);
block2: w[2] = –M[0]/EI;
POHYBOVÉ ÚSTROJÍ, ročník 19, 2012, č. 3+4 227