A retail benchmarking approach to efficient two‐way access pricing: no termination‐based price discrimination†

We study access pricing rules that determine the access prices between two networks as a linear function of marginal costs and (average) retail prices set by both networks. When firms compete in linear prices, there is a unique linear rule that implements the Ramsey outcome as the unique equilibrium, independently of underlying demand conditions. When firms compete in two‐part tariffs, there exists a class of rules under which firms choose the variable price equal to the marginal cost. Therefore, the regulator can choose among these rules to pursue additional objectives such as increasing consumer surplus or promoting socially optimal investment.     

Fast movement strategies for a step-and-scan wafer stepper

We describe algorithms for the determination of fast movement strategies for a step-and-scan wafer stepper, a device that is used for the photolithographic processing of integrated circuits. The proposed solution strategy consists of two parts. First, we determine the maximum number of congruent rectangular chips that can be packed on a wafer, subject to the restriction that the chips are placed in a rectangular grid. Second, we find fast movement strategies for scanning all chips of a given packing, given the mechanical restrictions of the wafer stepper. The corresponding combinatorial optimization problem is formulated as a generalized asymmetric traveling salesman problem. We show how feasible scan strategies are determined, and how these strategies are improved by local search techniques, such as iterative improvement based on 2- and 3-exchanges, and simulated annealing based on 2-exchanges.