The paper studies the two-echelon capacitated vehicle routing problem with time windows, in which delivery of freight from depots to customers is performed using intermediate facilities called satellites. We consider variant precedence constraints for unloading and loading at In this allows storage consolidation Thus, total transportation cost may decrease comparison alternative exact synchroni...

In this paper we analyze the interval availability of a two-echelon, multi-item spare part inventory system. We consider a scenario inspired by a situation that we encountered at Thales Netherlands, a manufacturer of naval sensors and naval command and control systems. Modeling the complete system as a Markov chain we analyze the interval availability. We compute in closed and exact form the ex...

Product take-back and recovery activities have grown in recent times as a consequence of stringent government regulations and increased customer awareness of environmental pollution. Inventory management in the context of product returns has drawn the attention of many researchers. However, the inherent complexity of the system with uncertain returns makes the analysis of the system extremely d...

In this paper, we address the Two-Echelon Vehicle Routing Problem (2E-VRP) in which freight is delivered from depots to intermediary satellites, from where it is delivered to customers. Different from other multi-level problems, the focus in 2E-VRP is on the global routing costs of the overall network. 2E-VRP has been recently introduced and, to our knowledge, there are no studies of the impact...

Clark and Scarf [1960] characterize optimal policies in a two-echelon, twolocation inventory model. We extend their result to the infinite-horizon case (for both discounted and average costs). The computations required are far easier than for the finite horizon problem. Further simplification is achieved for normal demands. We also consider the more interesting case of multiple locations at the...

In this paper, the previously introduced fuzzy modeling method is used to model the input impedance of two coupled dipole antennas in the echelon form. The initial data of two coupled dipole antennas in the parallel and collinear form, which are required for the model, are obtained using the MoM (Method of Moments). Then, the knowledge of two coupled dipole antennas in the echelon form is easil...

Cetacean mother-calf dyads demonstrate formation locomotion that may provide hydrodynamic and/or social benefits. For example, echelon position (calf in close proximity of its mother’s mid-lateral flank) enables calves to increase swim performance at reduced locomotor effort compared to periods of solitary swimming. Yet cetacean mother-calf dyads are also observed in infant position (calf in cl...

This paper is concerned with the numerical evaluation of multi-echelon production systems. Each stage requires a fixed predetermined leadtime; furthermore, we assume a stochastic, stauonary eLd.tlmc demand process. In a previous paper, we have developed an analytical framework for determining optimal control pohclcs for such systems under an average COSt criterion The current paper Is based on ...

In today’s globalization, the success of an industry is dependent on cost effective supply chain management under various markets, logistics and production uncertainties. Uncertainties in the supply chain usually decrease profit, i.e. increase total supply chain cost. Demand uncertainty and constraints posed by the every echelon are important factors to be considered in the supply chain design ...

This is an attempt to devise a memory efficient WDR (Wavelet Difference Reduction) algorithm by decomposing a matrix using customized Echelon algorithm and applying WDR on it in parts. The standard process of WDR algorithm requires the entire matrix to be available in RAM (random access memory) which might not be feasible always or for a longer duration till the entire matrix is encoded. This i...