Casestudie Breakdown prediction Contell PILOT - Transumo

could be: “The mean increase of a freezer’s electric power consumption is about 5%
per degree room ambient temperature”.
Functional models use functions to describe the existing behavior. ([Berthold99], p.
172) Finding a functional description can be very difficult and is not always possible.
A functional model of the freezer’s electric power consumption would allow a
calculation for every given room temperature. Furthermore, it could help predicting
malfunctions of a cooling device by just comparing current behavior to the describing
function.
Most powerful and detailed are analytic models. They describe coherences by the
use of algebraic or differential equations. This allows a very detailed description of
outputs for all kinds of imaginable inputs. ([Berthold99], p. 172) As already pointed
out in section 2.4.1, many in- and outputs and their coherences are unknown due to
very few sensors. That is why it seems to be impossible to find analytic models with
the currently available datasets.
Hence, this diploma thesis will first of all focus on possibilities to create statistical and
functional models to gain more detailed information of monitored cooling devices.
Only in case of reaching a degree of total information with this kind of models, an
attempt to determine an analytic model would be useful.
5.2 Different Kinds of Statistical Analysis
The general purpose of statistical analysis is to provide information to advance
important decisions. The main idea is to improve the quality of the decision making
process by reducing uncertainties as good as possible. In general, statistics is
divided into two branches: ([Holland01], p. 3)
1. Descriptive statistics
2. Inferential statistics
Descriptive statistical methods describe large available datasets. Their main purpose
is to summarize and to evaluate them. Another important task is the filtering of most
important facts to get an overview of the underlying dataset. Typical results of
descriptive statistical methods are statistical measures like the mean or the standard
deviation for instance. The results are presented in form of a table or a graph to offer
a quick overview. ([Holland01], p. 3)
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