3 research outputs found
An innovative artificial bee colony algorithm and its application to a practical intercell scheduling problem
<p>In this article, an innovative artificial bee colony (IABC) algorithm is proposed, which incorporates two mechanisms. On the one hand, to provide the evolutionary process with a higher starting level, genetic programming (GP) is used to generate heuristic rules by exploiting the elements that constitute the problem. On the other hand, to achieve a better balance between exploration and exploitation, a leading mechanism is proposed to attract individuals towards a promising region. To evaluate the performance of IABC in solving practical and complex problems, it is applied to the intercell scheduling problem with limited transportation capacity. It is observed that the GP-generated rules incorporate the elements of the most competing human-designed rules, and they are more effective than the human-designed ones. Regarding the leading mechanism, the strategies of the ageing leader and multiple challengers make the algorithm less likely to be trapped in local optima.</p
Coordinated scheduling of intercell production and intercell transportation in the equipment manufacturing industry
<p>Intercell moves are caused by exceptional parts which need to be processed in multiple cells. Intercell cooperation disrupts the cellular manufacturing philosophy of creating independent cells, but is essential to lower the costs for enterprises. This article addresses an intercell scheduling problem considering limited transportation capability. To solve this problem, a two-stage ant colony optimization approach is proposed, in which pre-scheduling and re-scheduling are performed sequentially. To evaluate and optimize the interaction of production and transportation, a transportation benefit function is presented, according to which the scheduling solutions are adjusted. The computational results show that the transportation benefit function is more effective than other strategies, and the proposed approach has significant advantages over CPLEX in both the production dimension and the transportation dimension.</p
Ring-opening polymerization of lactide using salen–aluminum complexes bearing Schiff-base ligands derived from <i>cis</i>-1,2-cyclohexanediamine
<p>Three aluminum complexes supported by salen ligands derived from <i>cis</i>-1,2-cyclohexanediamine and salicylaldehyde derivatives were synthesized. They were characterized by <sup>1</sup>H, <sup>13</sup>C NMR spectra, and elemental analysis. X-ray diffraction analysis revealed that aluminum was in distorted square pyramidal geometry in <b>2</b>. These complexes were employed as catalysts for the ring-opening polymerization (ROP) of L-lactide and <i>rac</i>-lactide. Complex <b>2</b> showed the highest activity among these complexes with isopropanol for the ROP of L-lactide and <b>3</b> showed the highest stereoselectivity for the ROP of <i>rac</i>-lactide attaining partially isotactic polylactide with a <i>P</i><sub>m</sub> of 0.75. The kinetic data of the polymerization utilizing <b>3</b> as catalyst showed that the polymeric rate was first order to the monomer and catalyst.</p