Search space, limitation

The computational equipment was a 3.06 GHz Xeon machine with 2 GB of main memory and Linux operating system. All tests were limited to five million of visited nodes and this limit was reached in all test runs. The configuration of the waiting list W of TAopt was depth-first search combined with cost minimization. In order to reduce the search effort, the search space was reduced by reduction techniques described in Panek et al. [22] with small modifications. Results of test runs with different initial quantities for So are shown in Table 10.2. The results show the computation times, the numbers of nodes visited to find the solution,... 

Irnidazo[ 1,2-tf ]py ridines were covered in CHEC(1984) <1984CHEC(6)613> along with others imidazoles fused to six-membered rings and they were reviewed together with imidazo[l,5- ]pyridines in CHEC-II(1996) <1996CHEC-II(8)249>. The chemical literature on this heterocycle is very abundant, due to its easy synthesis (most of the preparations use readily available 2-aminopyridines) and to the very broad spectrum of bioactivities displayed by many derivatives. A simple Beilstein search on the fully conjugated heterocycle (free sites everywhere) disclosed ca. 3000 hits for the past decade. Therefore, this chapter cannot be exhaustive in view of space limitations, but will mainly focus on the original synthetic methods that have appeared in the last decade. 

The above conditions limit the search space by removing candidates that are most likely not to satisfy the property constraints. 

While there was a growing number of non-soap detergents that either were already commercialized (as for use in laundry applications) or else had viable commercial potential, it was decided early on to limit the compositional search space to compositions using sodium acyl isethionates (SAI) as the primary surfactant. This decision was based on an early assessment of a prototype bar containing SAI which had been described in a 1952 French patent for which Unilever had acquired the rights [9], This prototype bar, with composition as described in Table 9.2-2, was referred to as the Monsavon bar. 

Many of the bioinformatics programs contain redundant information, so we try to differentiate them based on their applications. Only some of those most commonly used tools are discussed because of space limitation. Web sites mentioned in this chapter were accessed in October 2007. The most recent advances in the field can be updated through browsing these sites regularly as new databases and tools are often added. To facilitate up-to-date bioinformatics support, an integrated search engine and updated collections of tools are freely available at http //sysmed.pharmtao.com. 

One other problem is combinatorially large search spaces. There are 100 million potential candidates for rubber components formulation that are possible. Some other examples we have worked at Purdue have involved 1020 to 1030 different molecules. Another issue is that typically there are limited and uncertain data. Most often, combinatorial chemistry approaches do not succeed in these cases because obtaining the results is time and labor intensive. Fuel additives design, for example, requires dismantling the engine for every test of a new formula. 

Some can be excluded in order to limit the search space (e.g. local versus global) and the magnitude of GPT errors generated in evaluating the LPs, as explained in Section 2.2. 

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