scholarly journals An inventory model for multiple items assuming time-varying demands and limited storage

2021 ◽  
Author(s):  
Luis A. San-José ◽  
Manuel González-De-la-Rosa ◽  
Joaquín Sicilia ◽  
Jaime Febles-Acosta
Keyword(s):  
Inventory Model ◽  
Inventory Systems ◽  
Decision Makers ◽  
Time Dependent ◽  
Time Varying ◽  
Limited Capacity ◽  
Inventory Policy ◽  
Numerical Examples ◽  
Multiple Products ◽  
Theoretical Results

AbstractA model for inventory systems with multiple products is studied. Demands of items are time-dependent and follow power patterns. Shortages are allowed and fully backlogged. For this inventory system, our findings provide the efficient inventory policy that helps decision-makers to obtain the initial inventory levels and the reorder points that maximize the profit per unit time. Moreover, when it is assumed that the warehouse used for the storage of products has a limited capacity, the optimal inventory policy is also developed. The model presented here extends some inventory systems studied by other authors. Numerical examples are introduced to illustrate the applicability of the theoretical results presented.

Solution of Basic Inventory Model in Fuzzy and Interval Environments

2017 ◽  
pp. 65-95
Author(s):  
Sankar Prasad Mondal
Keyword(s):  
Differential Equation ◽  
Fuzzy Number ◽  
Interval Number ◽  
Inventory Model ◽  
Time Dependent ◽  
Equation Approach ◽  
Numerical Examples ◽  
Fuzzy Environment

In this present paper a basic inventory model is solved in different imprecise environments. Four different cases are discussed: 1) Crisp inventory model, that is, the quantity at present and demand is crisp number; 2) Inventory model in fuzzy environment, that is, the quantity and demand both are fuzzy number; 3) Inventory model in interval environment, that is, the quantity and demand both are interval number and lastly; 4) Inventory model in time dependent fuzzy environment, that is, quantity and demand are both time dependent fuzzy number. Different numerical examples are used to illustrate the model as well as to compute the efficiency of imprecise differential equation approach to solve the model.

scholarly journals Eulerian time-stepping schemes for the non-stationary Stokes equations on time-dependent domains

2022 ◽  
Author(s):  
Erik Burman ◽  
Stefan Frei ◽  
Andre Massing
Keyword(s):  
Parabolic Equation ◽  
Stokes Equations ◽  
A Priori ◽  
Time Dependent ◽  
Numerical Examples ◽  
Time Stepping ◽  
Discretisation Error ◽  
Moving Domains ◽  
Theoretical Results ◽  
Norm Error

AbstractThis article is concerned with the discretisation of the Stokes equations on time-dependent domains in an Eulerian coordinate framework. Our work can be seen as an extension of a recent paper by Lehrenfeld and Olshanskii (ESAIM: M2AN 53(2):585–614, 2019), where BDF-type time-stepping schemes are studied for a parabolic equation on moving domains. For space discretisation, a geometrically unfitted finite element discretisation is applied in combination with Nitsche’s method to impose boundary conditions. Physically undefined values of the solution at previous time-steps are extended implicitly by means of so-called ghost penalty stabilisations. We derive a complete a priori error analysis of the discretisation error in space and time, including optimal $$L^2(L^2)$$ L 2 ( L 2 ) -norm error bounds for the velocities. Finally, the theoretical results are substantiated with numerical examples.

scholarly journals Effects of Time-Varying Impulses on the Synchronization of Delayed Dynamical Networks

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Shuiming Cai ◽  
Peipei Zhou ◽  
Zengrong Liu
Keyword(s):  
Network Model ◽  
Comparison Principle ◽  
Network Topology ◽  
Spanning Tree ◽  
Time Varying ◽  
Dynamical Networks ◽  
Numerical Examples ◽  
General Complex ◽  
Delayed Dynamical Networks ◽  
Theoretical Results

The effects of time-varying impulses on the synchronization of a class of general complex delayed dynamical networks are investigated. Different from the existing works, the impulses discussed here are time-varying, and both synchronizing and desynchronizing impulses are considered in the network model simultaneously. Moreover, the network topology is assumed to be directed and weakly connected with a spanning tree. By using the comparison principle, some simple yet generic globally exponential synchronization criteria are derived. It is shown that besides impulse strengths and impulsive interval, the obtained criteria are also closely related with topology structure of the network. Finally, numerical examples are given to demonstrate the effectiveness of the theoretical results.

THE EFFECT OF CREDIT PERIOD ON THE OPTIMAL LOT SIZE FOR DETERIORATING ITEMS WITH TIME VARYING DEMAND AND DETERIORATION RATES

2005 ◽  
Vol 22 (02) ◽  
pp. 211-227 ◽  
Author(s):  
HORNG-JINH CHANG ◽  
CHUNG-YUAN DYE
Keyword(s):  
Inventory Model ◽  
Deteriorating Items ◽  
Simple Solution ◽  
Future Research ◽  
Time Varying ◽  
Lot Size ◽  
Credit Period ◽  
Numerical Examples ◽  
Varying Demand ◽  
Ordering Quantity

In this paper, we present an inventory model for deteriorating items with time varying demand and deterioration rates when the credit period depends on the retailer's ordering quantity. We also provide simple solution procedures for finding the optimal replenishment period and show in a rigorous way that the policy suggested is indeed optimal. Further, we use numerical examples to illustrate the model and conclude the paper with suggestions for possible future research.

OPTIMAL SUPERHEDGING UNDER NON-CONVEX CONSTRAINTS — A BSDE APPROACH

2008 ◽  
Vol 11 (04) ◽  
pp. 363-380 ◽  
Author(s):  
CHRISTIAN BENDER ◽  
MICHAEL KOHLMANN
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Numerical Methods ◽  
Borrowing Constraints ◽  
Time Dependent ◽  
Convex Constraints ◽  
Numerical Examples ◽  
Black Scholes ◽  
Backward Sdes ◽  
Theoretical Results

We apply theoretical results by Peng on supersolutions for Backward SDEs (BSDEs) to the problem of finding optimal superhedging strategies in a generalized Black–Scholes market under constraints. Constraints may be imposed simultaneously on wealth process and portfolio. They may be non-convex, time-dependent, and random. The BSDE method turns out to be an extremely useful tool for modeling realistic markets: in this paper, it is shown how more realistic constraints on the portfolio may be formulated via BSDE theory in terms of the amount of money invested, the portfolio proportion, or the number of shares held. Based on recent advances on numerical methods for BSDEs (in particular, the forward scheme by Bender and Denk [1]), a Monte Carlo method for approximating the superhedging price is given, which demonstrates the practical applicability of the BSDE method. Some numerical examples concerning European and American options under non-convex borrowing constraints are presented.

Forward and Inverse Analyses of an SMA Actuated Compliant Link

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
A. Banerjee ◽  
B. Bhattacharya ◽  
A. K. Mallik
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Large Deflection ◽  
Reference Signal ◽  
Input Voltage ◽  
Beam Element ◽  
Time Varying ◽  
Alloy Wire ◽  
Numerical Examples ◽  
Theoretical Results

This paper presents forward and inverse analyses of the response of a compliant link actuated by a discretely attached shape memory alloy (SMA) wire subjected to a time-varying input voltage. The framework for a constrained recovery of the shape memory alloy wire is developed from a robust numerical model. The model for the large deflection of a beam element due to follower forces resulting from discrete actuation using a SMA wire is coupled with the proposed framework. Thus, the response of the link is correlated with the input voltage. The algorithm for implementing this framework has been demonstrated along with some numerical examples. Experiments have also been conducted on a SMA actuated cantilever beam, and the results are compared with those of the simulations. A qualitative agreement between the two is observed. It is concluded that the theoretical results can provide a reference signal for active control of the link to achieve higher accuracy.

scholarly journals Integrated inventory model involving quality improvement investment and advance-cash-credit payments

2021 ◽  
Author(s):  
Chih-Te Yang ◽  
Chien-Hsiu Huang ◽  
Liang-Yuh Ouyang
Keyword(s):  
Optimal Solution ◽  
Inventory Model ◽  
Decision Makers ◽  
Optimal Solutions ◽  
Order Quantity ◽  
Defective Items ◽  
Numerical Examples ◽  
Proposed Model ◽  
Production Inventory ◽  
Total Profit

This paper investigates the effects of investment and inspection policies on an integrated production–inventory model involving defective items and upstream advance-cash-credit payment provided by the supplier. In this model, retailers offer customers a downstream credit period. Furthermore, the defective rate of the item can be improved through capital co-investment by the supplier and retailer. The objective of this study was to determine the optimal shipping quantity, order quantity, and investment alternatives for maximizing the supply chain's joint total profit per unit time. An algorithm was developed to obtain the optimal solution for the proposed problem. Several numerical examples are used to demonstrate the proposed model and analyze the effects of parameters changes on the optimal solutions. Finally, management implications for relevant decision makers are obtained from the numerical examples.

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