Light beam search

In reference point based methods, the DM first specifies a reference point z S consisting of desirable aspiration levels for each objective and then this reference point is projected onto the Pareto optimal set. That is, a Pareto optimal solution closest to the reference point is found. The distance can be measured in different ways. Specifying a reference points is an intuitive way for the DM to direct the search of the most preferred solution. It is straightforward to compare the point specified and the solution obtained without artificial concepts. Examples of methods of this t rpe are the reference point method and the light beam search . 

Another reference point based method is the light beam search (Jaszkiewicz and Slowinski, 1999). It uses a similar achievement function as the reference point method but combined with tools of multiattribute decision analysis (designed for comparing a discrete set of solutions). Besides a reference point, the DM must supply thresholds for objective functions describing indifference and preference in objective values. This information is used to derive outranking relations between solutions. As a result, incomparable or indifferent solutions are not displayed to the DM. 

Jaszkiewicz, A. and Slowinski, R. (1999). The light beam search approach - an overview of methodology and applications, European Journal of Operational Research 113, pp. 300-314. 

In a search for visible-light photoinitiators for stereolithography, the 6,8-diiodo-, 6-nitro-8-iodo-, and 6-nitro-7-methoxy-8-iodo- and T-benzyl-6-nitro-7-methoxy-8-iodoBIPS [respective Xmax (nm) and first-order half-lives for thermal fading (s) 606, 35 572, 330 568, 70 and 578, 15] were converted to their colored forms by heat or UV irradiation in solution in trimethylolpropane triacrylate containing added coinitiators. The benzyl compound with added A -phcnylglyciiie was the best initiator when irradiated with a 632-nm laser beam.114,115... 

Polymerization occurs when some outside agent provides the energy to break the double bond in ethylene to get the reaction started. Heat, light, ultraviolet radiation, a beam of electrons, and gamma rays have all been used to initiate polymerization. Polymerization occurs at lower energy levels, and it has been the search for catalysts to achieve this objective... 

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