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Casestudie Breakdown prediction Contell PILOT - Transumo

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Another current approach is regression. The main idea is to find a function that<br />

describes the temperature sequence best. A found function could be used for<br />

description as well as for <strong>prediction</strong> of future behavior ([Gentle02], p. 301). 34 Beside<br />

these presented approaches, artificial neural networks are applied again to gain<br />

additional knowledge (e.g. [Hawibowo97], p. 21-45). 35<br />

The succeeding chapter 5 will introduce the identified methods within this chapter<br />

and will test them on applicability to the setting of sensor based temperature<br />

monitoring. Before that, the next section introduces an approach that promises to be<br />

generalized. Hence, it should be applicable to the current problem.<br />

4.3.2 A Generalized Approach<br />

As already mentioned in section 4.3, Frank Daßler presents an approach that should<br />

be able to predict future measurement values without any knowledge of the<br />

underlying setting. The Main idea is to combine several known approaches to a new<br />

one. ([Daßler95], p. 7-8)<br />

The presented approach is based on the idea to solve the problem of just setting<br />

critical limits. According to the author, these existing methods lead to three problems:<br />

([Daßler95], p. 19)<br />

1. Just setting critical limits leads to sudden changes of current state. As long as<br />

a value does not exceed the predefined range, the state is classified as OK.<br />

2. In the moment of exceeding, an immediate reaction is necessary to solve<br />

dangerous situations.<br />

3. Chosen limits with a lower span to reduce situations of immediate danger lead<br />

to a higher quantity of false alarms due to outliers.<br />

Figure 4-1 illustrates the general proceeding of the new approach, which shall be<br />

able to solve the just mentioned problems:<br />

34 See section 5.4 for details<br />

35 See section 5.9.2 for details<br />

47

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