scholarly journals Storage Assignment Optimization in Robotic Mobile Fulfillment Systems

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ruiping Yuan ◽  
Juntao Li ◽  
Wei Wang ◽  
Jiangtao Dou ◽  
Luke Pan
Keyword(s):  
Turnover Rate ◽  
Simulation Experiment ◽  
Order Picking ◽  
Assignment Method ◽  
Total Correlation ◽  
Storage Assignment ◽  
New Type ◽  
The Difference ◽  
The Times ◽  
Picking System

Robotic mobile fulfillment system (RMFS) is a new type of parts-to-picker order picking system, where robots carry inventory pods to stationary pickers. Because of the difference in working mode, traditional storage assignment methods are not suitable for this new kind of picking system. This paper studies the storage assignment optimization of RMFS, which is divided into products assignment stage and pods assignment stage. In the products assignment stage, a mathematical model maximizing the total correlation of products in the same pods is established to reduce the times of pod visits, and a scattered storage policy is adopted to reduce system congestion. A heuristic algorithm is designed to solve the model. In the pods assignment stage, a model is established minimizing the total picking distance of the mobile robots considering the turnover rate and the correlation of pods as well as the workload balance among picking corridors. A two-stage hybrid algorithm combining greedy algorithm and improved simulated annealing is designed to solve the model. Finally, a simulation experiment is carried out based on the historical order data of an e-commerce company. Results show that the storage assignment method proposed in the paper significantly improves the efficiency of order picking.

An integrated storage assignment method for manual order picking warehouses considering cost, workload and posture

2018 ◽  
Vol 57 (8) ◽  
pp. 2392-2408 ◽  
Author(s):  
Martina Calzavara ◽  
Christoph H. Glock ◽  
Eric H. Grosse ◽  
Fabio Sgarbossa
Keyword(s):  
Order Picking ◽  
Assignment Method ◽  
Storage Assignment

Study on the working state of the five hundred-meter aperture spherical telescope using step-wise assignment method

2014 ◽  
Vol 229 (2) ◽  
pp. 316-324 ◽  
Author(s):  
Yu Liu ◽  
Feng Gao
Keyword(s):  
Nonlinear Equations ◽  
Analytical Solutions ◽  
Driving Mechanism ◽  
Initial Value ◽  
Unknown Parameters ◽  
Support Structure ◽  
Assignment Method ◽  
New Type ◽  
Set Up ◽  
The Mathematical Model

The working state of the five hundred-meter aperture spherical telescope (FAST) is solved using the step-wise assignment method. In this paper, the mathematical model of the cable-net support structure of the FAST is set up by the catenary equation. There are a large number of nonlinear equations and unknown parameters of the model. The nonlinear equations are solved by using the step-wise assignment method. The method is using the analytical solutions of the cable-net equations of one working state as the initial value for the next working state, from which the analytical solutions of the nonlinear equations of the cable-net for each working state of the FAST and the tension and length of each driving cable can be obtained. The suggested algorithm is quite practically well suited to study the working state of the cable-net structures of the FAST. Also, the working state analysis result of the cable-net support structure of a reduced model of the cable-net structure reflector for the FAST is given to verify the reliability of the method. In order to show the validity of the method, comparisons with another algorithm to set the initial value are presented. This method has an important guiding significance to the further study on the control of the new type of flexible cable driving mechanism, especially the FAST.

The Magnetic Anisotropy of Stretched Rubber as a Function of the Tension to Which It Is Subjected

1945 ◽  
Vol 18 (1) ◽  
pp. 8-9 ◽  
Author(s):  
Eugénie Cotton-Feytis
Keyword(s):  
Magnetic Field ◽  
Magnetic Anisotropy ◽  
Uniaxial Crystal ◽  
Horizontal Magnetic Field ◽  
First Approximation ◽  
The Difference ◽  
The Times ◽  
Angular Displacements ◽  
The Magnetic Field ◽  
Oscillation Method

Abstract From the standpoint of its magnetic anisotropy, stretched rubber is comparable in a first approximation to a uniaxial crystal, in which the direction of the axis is the same as the direction of elongation. It is possible to measure this anisotropy by means of the oscillation method used by Krishnan, Guha and Banerjee in studying crystals. The sample to be examined is suspended in a uniform horizontal magnetic field in such a manner that its axis is horizontal. It is then so arranged that the torsion of the suspension wire is zero when the rubber sample is in a position of equilibrium in the field. The times of oscillation T′ and T for very small angular displacements around this position, in the presence and then in the absence of the magnetic field, are then recorded. In this way the difference between the specific susceptibilities in the direction of the axis and in the horizontal direction perpendicular to the axis is calculated by application of the equation:

CLINICAL TRIAL OF HUMAN GONADOTROPHINS

1966 ◽  
Vol 53 (3_Suppl) ◽  
pp. S3-S26 ◽  
Author(s):  
A. C. Crooke ◽  
W. R. Butt ◽  
P. V. Bertrand
Keyword(s):  
Clinical Trial ◽  
Dose Response ◽  
Positive Response ◽  
Test Dose ◽  
Sufficient Data ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Individual Sensitivity ◽  
The Difference ◽  
The Times

ABSTRACT Thirteen patients with prolonged secondary amenorrhoea and 5 with anovular cycles each provided sufficient data to establish their individual sensitivity to FSH. The parameters used were based on the rise in excretion of oestriol and of pregnanediol. The sensitivity expressed as the ED 50 (that dose which is effective in 50 per cent of times it is given) varied between patients over at least a sevenfold range but the difference between the 2 groups of patients was not significant. After adjusting for differences between patients a dose-response relationship was established and it was found that a dose equal to half the ED 50 would be expected to produce a response in less than Io per cent of the times it is given while a dose equal to twice the ED 50 would be expected to produce a response in more than go per cent of the times it is given. Such a dose would be likely to produce an excessive response. An excessive response occurred three times in 140 months of treatment. Sixteen of the I8 patients became pregnant. The 2 who failed gave up treatment prematurely. A test of individual patient's sensitivity to FSH was established which depended on single injections of the hormone mixed with HCG. The test was repeated at 2 to 3 weekly intervals with increasing dosages until a positive response was obtained as judged by an increase in excretion of oestriol. The rate at which the dose should be increased was investigated and a 30 per cent rate was selected. When the effective test dose was established a standard schedule of dosages was recommended for treatment using 3 equal doses of FSH in 8 days and HCG on the tenth.

New analysis of holophotoelastic patterns and their application

1976 ◽  
Vol 11 (1) ◽  
pp. 11-17 ◽  
Author(s):  
J Ebbeni ◽  
J Coenen ◽  
A Hermanne
Keyword(s):  
Numerical Methods ◽  
Dynamic Problems ◽  
Principal Stresses ◽  
Optical Elements ◽  
New Type ◽  
The Difference ◽  
Fringe Patterns

This paper shows that by the use of a new type of diffuser it is possible in photo-holoelasticimetry, without any addition of optical elements or particular preparation of the specimen, to record simultaneously but separately fringe patterns respectively related to the sum and the difference of the principal stresses. The value of intensity of the interfering light reaching the hologram plate is established and hence the equations of the recorded pseudoisopachic fringe patterns are given. Used successfully for the study of particular static problems, where numerical methods are very difficult or impossible, the present interferometer is also suited for dynamic problems.

scholarly journals Simulation Model for a Semi-automated Retail Order Picking System Under Uncertainty

2021 ◽  
pp. 759-767
Author(s):  
Sawssen Souiden ◽  
Audrey Cerqueus ◽  
Xavier Delorme ◽  
Jean-Lucien Rascle
Keyword(s):  
Simulation Model ◽  
Order Picking ◽  
Picking System
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