Civil Engineering Reference
In-Depth Information
Fig. 13.5
Triangular
distribution
f
(x)
X
−
a
0
a
Fig. 13.6
Uniform
distribution
13.8.6
Uniform Distribution
Uniform distribution (Fig.
13.6
) is a subcategory of discrete distribution where a
fi nite number of equally spaced values are equally likely to be observed; in other
word every one of
n
values has equal probability of occurrence of 1/
n
.
It is most useful in simulation where attention should be given to a poorly defi ned
parameter, say at the early design stage. The distribution is the most suitable for
modeling systematic errors as these errors are not random and hence the true value
is equally probable throughout the given range (McDonald
2002
).
13.9
Uncertainty in Energy Modeling
When we through an energy modeling exercise attempt to predict the cooling and
heating systems energy consumption, it implies that we are making assumptions
about the system components performances. These assumptions derive from our
lack of knowledge (uncertainty) about how close to our expectations these compo-
nents could actually perform. Therefore quantifying these uncertainties if it is pos-
sible, in fact can be very helpful for almost every group of people who are engaged
and have role in design and construction of the building industry. Design engineers
can use these quantifi ed measures to select a better component and system and
