Algorithm strategy

Applying the above algorithmic strategy, the optimal solution found, shown in Figure 9.6, has a total annual cost of 156,710. It features (i) task II first and then task I, (ii) a total by-pass of the feed to the two products, and (iii) the bottoms of task II is directed to product P2. 

The same example was solved using MINOPT (Rojnuckarin and Floudas, 1994) by treating the PFR model as a differential model. The required input files are shown in the MINOPT manual. Kokossis and Floudas (1990) applied the presented approach for large-scale systems in which the reactor network superstructure consisted of four CSTRs and four PFR units interconnected in all possible ways. Each PFR unit was approximated by a cascade of equal volume CSTRs (up to 200-300 CSTRs in testing the approximation). Complex reactions taking place in continuous and semibatch reactors were studied. It is important to emphasize that despite the complexity of the postulated superstructure, relatively simple structure solutions were obtained with the proposed algorithmic strategy. 

After selecting a measure one has to decide which clustering algorithm (strategy) may be appropriate. Sometimes it is necessary for the algorithm to fit the similarity measure. In most cases one wishes to use the algorithm which yields the most interpretable or plausible data structure. 

Fig. 19 Evolutionary optimisation at the atomic level. A combination of rule-based and genetic algorithm strategies is used to coerce an STM tip to produce one of two distinct image types, with no human operator involvement, (a) and (b) are the experimental images (c) and (d) the target structures (e) and (f) show profiles along the lines shown in (a) and (b). From Ref. 82.

There are several basic strategies for the improvement of the performance of substructure search algorithms ... 

Current research in LHASA is focused on developing new methods assisting users in choosing the most appropriate strategy for their target structures. Furthermore, the development of criteria for the evaluation of synthesis routes and/or algorithms for selecting optimal synthesis routes within the tree are discussed [34]. 

Some of the inherent advantages of the feedback control strategy are as follows regardless of the source or nature of the disturbance, the manipulated variable(s) adjusts to correct for the deviation from the setpoint when the deviation is detected the proper values of the manipulated variables are continually sought to balance the system by a trial-and-error approach no mathematical model of the process is required and the most often used feedback control algorithm (some form of proportional—integral—derivative control) is both robust and versatile. 

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