39,243 research outputs found
Active repositioning of storage units in Robotic Mobile Fulfillment Systems
In our work we focus on Robotic Mobile Fulfillment Systems in e-commerce
distribution centers. These systems were designed to increase pick rates by
employing mobile robots bringing movable storage units (so-called pods) to pick
and replenishment stations as needed, and back to the storage area afterwards.
One advantage of this approach is that repositioning of inventory can be done
continuously, even during pick and replenishment operations. This is primarily
accomplished by bringing a pod to a storage location different than the one it
was fetched from, a process we call passive pod repositioning. Additionally,
this can be done by explicitly bringing a pod from one storage location to
another, a process we call active pod repositioning. In this work we introduce
first mechanisms for the latter technique and conduct a simulation-based
experiment to give first insights of their effect
Joint effect of lattice interaction and potential fluctuation in colossal magnetoresistive manganites
Taking into account both the Jahn-Teller lattice distortion and the on-site
electronic potential fluctuations in the orbital-degenerated double-exchange
model, in which both the core-spin and the lattice distortion are treated
classically, we investigate theoretically the metal-insulator transition (MIT)
in manganites by considering the electronic localization effect. An inverse
matrix method is developed for calculation in which we use the inverse of the
transfer matrix to obtain the localization length. We find that within
reasonable range of parameters, both the lattice effect and the potential
fluctuation are responsible to the occurrence of the MIT. The role of the
orbital configuration is also discussed.Comment: 4 figure
Radiative Neutrino Mass, Dark Matter and Leptogenesis
We propose an extension of the standard model, in which neutrinos are Dirac
particles and their tiny masses originate from a one-loop radiative diagram.
The new fields required by the neutrino mass-generation also accommodate the
explanation for the matter-antimatter asymmetry and dark matter in the
universe.Comment: 4 pages, 3 figures. Revised version with improved model. Accepted by
PR
An advanced meshless method for time fractional diffusion equation
Recently, because of the new developments in sustainable engineering and renewable energy, which are usually governed by a series of fractional partial differential equations (FPDEs), the numerical modelling and simulation for fractional calculus are attracting more and more attention from researchers. The current dominant numerical method for modeling FPDE is Finite Difference Method (FDM), which is based on a pre-defined grid leading to inherited issues or shortcomings including difficulty in simulation of problems with the complex problem domain and in using irregularly distributed nodes. Because of its distinguished advantages, the meshless method has good potential in simulation of FPDEs. This paper aims to develop an implicit meshless collocation technique for FPDE. The discrete system of FPDEs is obtained by using the meshless shape functions and the meshless collocation formulation. The stability and convergence of this meshless approach are investigated theoretically and numerically. The numerical examples with regular and irregular nodal distributions are used to validate and investigate accuracy and efficiency of the newly developed meshless formulation. It is concluded that the present meshless formulation is very effective for the modeling and simulation of fractional partial differential equations
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