In this paper, a mathematical programming model is presented for integrated problem of closed loop supply chain network design and supplier selection. The suppliers  propose discount policy based on purchase amount and loyalty of buyers which are both taken from the elements of RFM (Recency, Frequency and Monetary) technique. The main objective of this paper which is formulated by a mixed-integ...

The research on service supply chain has attracted more and more focus from both academia and industrial community. In a service supply chain, the selection of supplier portfolio is an important and difficult problem due to the fact that a supplier portfolio may include multiple suppliers from a variety of fields. To address this problem, we propose a novel supplier portfolio selection method b...

High amounts of waste paper are disposed of every year in Iran posing the health hazard and environmental damages instead of being recovered. Collection, recovery and proper disposal of waste paper without damaging the environment need to design an efficient closed-loop supply chain network. The main objective of this paper is introducing a bi-objective, multi-echelon, multi-product and single-...

Highly optimized complex transport networks serve crucial functions in many man-made and natural systems such as power grids and plant or animal vasculature. Often, the relevant optimization functional is nonconvex and characterized by many local extrema. In general, finding the global, or nearly global optimum is difficult. In biological systems, it is believed that such an optimal state is sl...

This study explores the drivers of site selection amongst livestock owners under conditions of increasing animal numbers following a low point in the 1990s. Our major goal was to understand whether livestock owners are acting as 'optimal foragers,' targeting areas of highest forage availability as they colonise previously empty areas. The results presented here suggest that they do not. Initial...

The main impetus for 'modern' intensive animal production occurred after the Second World War, when Western governments developed policies to increase the availability of cheap, safe food for their populations. Livestock benefit under intensive husbandry by protection from environmental extremes and predators, and better nutritional and health management. Nevertheless, there are costs to the an...

Van Valen's model, which relates morphological variation to ecological variation in an adaptive scheme, was investigated with individually marked and measured Darwin's finches on two adjacent Galápagos islands, Santa Cruz and Daphne Major. Results show that environmental heterogeneity is correlated with large continuous, morphological variation: variation in bill dimensions of Geospiza fortis i...

The market-based approach to manufacturing supply network planning focuses on the competitive attitudes of various enterprises in the network to generate plans that seek to maximize the throughput of the network. It is this competitive behaviour of the member units that we explore in proposing a solution model for a supplier selection problem in convergent manufacturing supply networks. We pres...