Approximation Algorithms for a New Truck Loading Problem in Urban Freight Transportation

2020 ◽  
Vol 54 (3) ◽  
pp. 690-702
Author(s):  
Jie Fan ◽  
Guoqing Wang ◽  
Matthias Thürer

Motivated by urban freight transportation practices in China, we study an optimal truck loading problem in which a fixed cost and an additional cost that depends on the number of unloading points are associated with each truck used. The truck loading problem is modeled as a one-dimensional bin packing problem, where the cost of each bin is a convex fixed-plus-linear function of the number of items in the bin. The objective is to minimize the total cost of bins used. We develop an asymptotic polynomial time approximation scheme and an efficient approximation algorithm with an asymptotic worst-case performance ratio of 1.5 to tackle the problem. Our computational experiments indicate that the approximation algorithm performs well for certain order patterns, and also reveal several important insights on using the freight charge scheme.

1999 ◽  
Vol Vol. 3 no. 4 ◽  
Author(s):  
Keqin Li

International audience In this paper, we consider the problem of scheduling independent parallel tasks in parallel systems with identical processors. The problem is NP-hard, since it includes the bin packing problem as a special case when all tasks have unit execution time. We propose and analyze a simple approximation algorithm called H_m, where m is a positive integer. Algorithm H_m has a moderate asymptotic worst-case performance ratio in the range [4/3 ... 31/18] for all m≥ 6; but the algorithm has a small asymptotic worst-case performance ratio in the range [1+1/(r+1)..1+1/r], when task sizes do not exceed 1/r of the total available processors, where r>1 is an integer. Furthermore, we show that if the task sizes are independent, identically distributed (i.i.d.) uniform random variables, and task execution times are i.i.d. random variables with finite mean and variance, then the average-case performance ratio of algorithm H_m is no larger than 1.2898680..., and for an exponential distribution of task sizes, it does not exceed 1.2898305.... As demonstrated by our analytical as well as numerical results, the average-case performance ratio improves significantly when tasks request for smaller numbers of processors.


Author(s):  
Ol'ga Lebedeva

The well-known approaches to the process of modeling the demand in urban freight transportation in conditions of limited availability of adequate data are considered. The main task is to select a model for creating a reliable system for analyzing urban freight traffic. Demand assessment models were chosen as input data because they are the most representative for assessing urban freight transport performance.


2019 ◽  
Vol 67 ◽  
pp. 491-502 ◽  
Author(s):  
Renata Albergaria de Mello Bandeira ◽  
George Vasconcelos Goes ◽  
Daniel Neves Schmitz Gonçalves ◽  
Márcio de Almeida D'Agosto ◽  
Cíntia Machado de Oliveira

2018 ◽  
Vol 184 ◽  
pp. 727-739 ◽  
Author(s):  
Renata A.M. Bandeira ◽  
Marcio A. D'Agosto ◽  
Suzana K. Ribeiro ◽  
Adriano P.F. Bandeira ◽  
George V. Goes

1990 ◽  
Vol 01 (02) ◽  
pp. 131-150 ◽  
Author(s):  
KEQIN LI ◽  
KAM-HOI CHENG

We investigate the two and three dimensional bin packing problems, i.e., packing a list of rectangles (boxes) into unit square (cube) bins so that the number of bins used is a minimum. A simple on-line packing algorithm for the one dimensional bin packing problem, the First-Fit algorithm, is generalized to two and three dimensions. We first give an algorithm for the two dimensional case and show that its asymptotic worse case performance ratio is [Formula: see text]. The algorithm is then generalized to the three dimensional case and its performance ratio [Formula: see text]. The second algorithm takes a parameter and we prove that by choosing the parameter properly, it has an asymptotic worst case performance bound which can be made as close as desired to 1.72=2.89 and 1.73=4.913 respectively in two and three dimensions.


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