As a non-parametric method of relative efficient measurement of a group of decision-making units (〖DMU〗_s), Data Envelopment Analysis (DEA) is one of the most important tools in efficiency computation. One of the main concerns dealt with in DEA is dealing with return to scale in two-stage processes in which, produced outputs of the first stage inputs are used as inputs for the second stage. The...

Based on the recently constructed Escherichia coli itaconic acid production strain ita23, we aimed to improve the productivity by applying a two-stage process strategy with decoupled production of biomass and itaconic acid. We constructed a strain ita32 (MG1655 ΔaceA Δpta ΔpykF ΔpykA pCadCs), which, in contrast to ita23, has an active tricarboxylic acid (TCA) cycle and a fast growth rate of 0.5...

This paper considers the case of a one-stage production system with several products and operating under tight production capacity constraints. The production schedule is cyclical, and there are long and sequence dependent setup times. The production system is regarded to consist of two components, namely a production unit and an inventory unit. The performance, with respect to inventory costs,...

This paper studies operations sequencing for a multi-stage production inventory system with lead times under predictable (deterministic) yield losses in the presence of uncertain demand, with full or partial release of work-in-process (WIP) inventories, for preor post-operation cost structures, and under the total discounted or average cost criteria. We derive necessary and sufficient criteria ...

With the large-scale production of plug-in electric vehicles (PEVs), a new entity, the PEV fleet aggregator manages charging and discharging processes of the vehicles. The main objective of an individual aggregator in interaction with electricity markets is maximizing its profit. In this paper, the performance of this aggregator in day-ahead and real-time electricity markets, considering (a) cu...