A New Mathematical Programming Framework for Facility Layout Design

We present a new framework for efficiently finding competitive solutions for the facility layout problem. This framework is based on the combination of two new mathematical programming models. The first model is a relaxation of the layout problem and is intended to find good starting points for the iterative algorithm used to solve the second model. The second model is an exact formulation of the facility layout problem as a non-convex mathematical program with equilibrium constraints (MPEC). Aspect ratio constraints, which are frequently used in facility layout methods to restrict the occurrence of overly long and narrow departments in the computed layouts, are easily incorporated into this new framework. Finally, we present computational results showing that both models, and hence the complete framework, can be solved efficiently using widely available optimization software. This important feature of the new framework implies that it can be used to find competitive layouts with relatively little computational effort. This is advantageous for a user who wishes to consider several competitive layouts rather than simply using the mathematically optimal layout

Advances in Pathway Engineering for Natural Product Biosynthesis

Biocatalysts provide an efficient, inexpensive and environmentally friendly alternative to traditional organic synthesis, especially for compounds with complex stereochemistries. The past decade has seen a significant rise in the use of biocatalysts for the synthesis of compounds in an industrial setting; however, the incorporation of single enzymatically catalysed steps into organic synthesis schemes can be problematic. The emerging field of synthetic biology has sparked interest in the development of whole-cell factories that can convert simple, common metabolites into complex, high-value molecules with a range of applications such as pharmaceuticals and biofuels. This Review summarises conventional methods and recent advances in metabolic engineering of pathways in microorganisms for the synthesis of natural products

Efficient algorithms for grouping component-processor families

Includes bibliographical references (p.24-25)

On finding minimal bottleneck cells for grouping component processor families

Includes bibliographical references (p. 18-19)

Advanced Search Techniques For Circuit Partitioning

. Most real world problems especially circuit layout and VLSI design are too complex for any single processing technique to solve in isolation. Stochastic, adaptive and local search approaches have strengths and weaknesses and should be viewed not as competing models but as complimentary ones. This paper describes the application of a combined Tabu Search [1] and Genetic Algorithm heuristic to guide an efficient interchange algorithm to explore and exploit the solution space of a hypergraph partitioning problem. Results obtained indicate, that the generated solutions and running time of this hybrid are superior to results obtained from a combined eigenvector and node interchange method [11]. 1. Introduction In the combinatorial sense, the layout problem is a constrained optimization problem. We are given a description of a circuit (usually called a netlist) which is a description of switching elements and their connecting wires. We seek an assignment of geometric coordinates of the ci..

Clustering analysis : models and algorithms / 1192

Includes bibliographical references (p. 27-29)