This paper presents a comparative study of the critical pickup and saltation velocities of particles in horizontal pipelines for pneumatic conveying design. A comparative study is performed using different existing correlations in the literature for the determination of the minimum velocity of transport as a function of the particle and pipe diameter, particle density, solid mass flow rate and ...

We consider a real-world problem arising in a warehouse for spare parts. Items ordered by customers shall be collected and for this purpose our task is to determine efficient pickup tours within the warehouse. The algorithm we propose embeds a dynamic programming algorithm for computing individual optimal walks through the warehouse in a general variable neighborhood search (VNS) scheme. To enh...

In pickup and delivery problems (PDPs), vehicles pickup and deliver a set of items under various constraints. We address the PDP with Transfers (PDP-T), in which vehicles plan to transfer items between one another to form more efficient schedules. We introduce the Very Large Neighborhood Search with Transfers (VLNS-T) algorithm to form schedules for the PDP-T. Our approach allows multiple trans...

We present an analysis of the reading capability of a novel optical pickup consisting of a single-mode and a multi-mode rectangular waveguide. According to the simulations, if one has prior information about the structure of the disk, superresolution readout could be achieved. The proposed system has the advantage to be compact and should be straightforward to be extended to arrays. The working...

The PDPTW is an optimization vehicles routing problem which must meet requests for transport between suppliers and customers satisfying precedence, capacity and time constraints. We present, in this paper, a genetic algorithm for multi-objective optimization of a dynamic multi pickup and delivery problem with time windows (Dynamic m-PDPTW). We propose a brief literature review of the PDPTW, pre...

An analytic expression describing the complex voltage measured between the pickup points of a four-point probe, in contact with the surface of a half-space conductor, is derived. The driving current is assumed to be time harmonic. There are two contributions to the measured voltage. One arises from the potential drop due to electric current flowing in the conductor. The other arises from induct...

The arrivals forecast is one of the key inputs for a successful hotel revenue management system, but no research on the best forecasting method has been conducted. In this research, we used data from Choice Hotels and Marriott Hotels to test a variety of forecasting methods and to determine the most accurate method. Preliminary results using the Choice Hotel data show that pickup methods and re...

We describe a constraint programming approach for a supplydelivery problem in the petrochemical industry, in which barges transport liquid material from supplier locations to downstream processing plants. The problem is to design a pickup-and-delivery route for each barge such that given minimum and maximum inventory levels at each location are met for a given fleet size. This optimization prob...