This work studies a multi-echelon multi-item lot-sizing problem with remanufacturing and lost sales. The is formulated as mixed-integer linear program. A new family of valid inequalities taking advantage the structure introduced used in customized branch-and-cut algorithm. provided numerical results show that proposed algorithm outperforms both generic embedded standard-alone mathematical solve...

In this paper, topological properties of Wijsman hyperspaces are investigated. We study the existence of isolated points in Wijsman hyperspaces. We show that every Tychonoff space can be embedded as a closed subspace in the Wijsman hyperspace of a complete metric space which is locally R.

We report 60 and 90 m observations of seven millisecond pulsars with the Infrared Space Observatory. The pulsar PSR B1257+12 is orbited by three planets, and other millisecond pulsars may be orbited by dust disks that represent planets that failed to form or their residue. We do not detect any infrared emission from the seven pulsars in our sample, and typical upper limits are 100 mJy. Using a ...

In 1996 the sale and export of food aid from refugee camps near Uvira, Zaire, prompted a reduction in donated rations. However, research has revealed that the sales did not reflect an excess of food in the camps. They were provoked by the absence of important components of the food basket, by cultural aversion to the staple (maize) and oil provided, by difficulties in food preparation, and by t...

This contribution is concerned with the value of RFID for retail store operations, particularly the use of the technology to automate shelf replenishment decisions. We construct and test an inventory control policy based on RFID data with case-level tagging. Our model incorporates RFID hardware capable of detecting bidirectional product movements between a store's backroom and the sales floor. ...

Until recently, the modern pharmaceutical industry has never stopped growing since the mid-1800s. Drugs such as morphine, quinine, amphetamine, antidepressants, barbiturates, insulin, anti-inflammatory drugs and many others have generated extensive revenues for the so-called Big Pharma [1]. Unfortunately, several significant changes have occurred a few years ago. The 2008 worldwide crisis has b...

Problem definition: Is deep reinforcement learning (DRL) effective at solving inventory problems? Academic/practical relevance: Given that DRL has successfully been applied in computer games and robotics, supply chain researchers companies are interested its potential management. We provide a rigorous performance evaluation of three classic intractable problems: lost sales, dual sourcing, multi...

The Bass di®usion model is a well-known parametric approach to estimating new product demand trajectory over time. This paper generalizes the Bass model by allowing for a supply constraint. In the presence of a supply constraint, potential customers who are not able to obtain the new product join the waiting queue, generating backorders, and potentially reversing their adoption decision, result...