Randomizing segmental exchange

Since each batch ID must occur a certain number of times (as often as the number of recipe steps of the batch), a recombination operator that preserves permutations is applied. The two best individuals out of a set of randomly chosen individuals are selected from the population. Then a random segment is copied from the first individual into a new individual. The missing elements are filled with the entries of the second individual. The newly generated individual is then subject to mutation with a probability p. By mutation, two randomly chosen entries are exchanged. 

Isotope exchange can also be useful in detecting partially random segments in what otherwise appears to be an ordered sequence this situation appears frequently in enzyme kinetics. For example, if increasing [B] and [P] in an Ordered Bi Bi mechanism yields significant substrate inhibition, but the exchange velocity cannot be driven to zero, that is, the plot intersects the i/vo-axis at a finite value, then we may suspect that some degree of randomness is present. 

Adsorption. When each segment can adsorb reversibly onto a particle with energy comparable to kT, the chain assumes a configuration (Fig. lb) quite different from the random coil in bulk solution (Fig. la). At equilibrium, bound and free segments rapidly interchange within the adsorbed chains, but bound and free chains exchange much more slowly. 

Mecham, J.B. (2001) Direct polymerization of snlfonated poly (arylene ether) random copolymers and poly(imide) sulfonated poly(arylene ether) segmented copolymers new candidates for proton exchange membrane fuel cell material systems. Ph.D. Thesis, Virginia Polytechnic Institute and State University. 

Operators that may be applied to parents when they reproduce to tilter their genetic composition, such as crossover (i.e., exchanging a randomly selected segment between parents), mutation (i.e., gene modification), and other domain-specific operators... 

Step reaction copolymers tend to be more or less random. Even with different monomer reactivities that lead initially to non-random copolymers, randomization is ultimately helped by interchange reactions that can proceed after the initial polymerization. Figure 3.47 illustrates the interchange of chain segments by transesterification. One molecule has the chain-ends R, and R2, the other R3 and R4. After the reaction, the ends are exchanged. 

Crossover Form two offspring candidate solutions (trees) from each randomly selected pair of parent trees from the parent pool. Crossover can be performed multiple ways. For example, in the single-point crossover shown in Fig. 3.59c, a location is selected randomly within the stractnre of each parent tree. Next, the respective trees are spliced at that location and offspring candidate solntions are created by mutually exchanging and combining the spliced segments of the parent trees. 

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