Rule-based activities

These results are directly compatible with models of human information processing (Rasmussen, 1983). Calculation is, in most cases, a skill-and-rule-based activity and requires relatively little mental effort. In contrast to this, selection and evaluation, as well as the activities around task clarification, are more rule-and knowledge-based tasks that require higher mental effort. According to the stress-strain concept, these phases result in a higher strain level. 

Many of these errors occur because the boundary between skill-based and rule-based activity has not been correctly respected. 

To verify that there was no obvious redundancy in the assay data, a subset of 80 assays and 1600 compounds was analyzed using the KEM approach [19-21] developed by Ariana [22], a systematic rule-based method that identifies all relations of the type A —> B, A and B —> C and not D. No such noncontradicted relations were found, even using very large activity bins, showing that there is signal in all the assay data, including those from related assays. 

Both infrared (IR) and Raman spectroscopy have selection rules based on the symmetry of the molecule. Any molecular vibration that results in a change of dipole moment is infrared active. For a vibration to be Raman active, there must be a change of polarizability of the molecule as the transition occurs. It is thus possible to determine which modes will be IR active, Raman active, both, or neither from the symmetry of the molecule (see Chapter 3). In general, these two modes of spectroscopy are complementary specifically, if a molecule has a center of symmetry, no [R active vibration is also Raman active. 

There are activated carbons of high purity available on the market. The general rule is that synthetic-based activated carbons have much lower impurity content than natural-based activated carbons. They are nevertheless not widely used because their prices are 4-10 times much more expensive. 

Schuffenhauer A, Brown N, Ertl P, Jenkins JL, Selzer P, Hamon J. Clustering and rule-based classifications of chemical structures evaluated in the biological activity space. Chem. Inf. Model. 47. 2007 47 325-336. 

DEREK (also see Chapter 18) is an expert or rule-based system with a list of chemical substructures correlated with mutagenic activity [24], The model was built using published mutagenic mechanism-of-action data and a list of known mutagenic structural alerts derived from Ashby s list of DNA reactive electrophilic chemical fragments [2,24,25]. Because this is a rule-based system, the... 

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