scholarly journals Mathematical Model for Cargo Allocation Problem in Synchromodal Transportation

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 540
Author(s):  
Nijolė Batarlienė ◽  
Raimondas Šakalys
Keyword(s):  
Mathematical Model ◽  
Integer Programming ◽  
Environmental Impact ◽  
Waiting Time ◽  
Optimization Model ◽  
Traffic Management ◽  
Transport Process ◽  
Programming Model ◽  
Stochastic Integer Programming ◽  
Optimization Task

Synchromodality is a freight transport process in which information is exchanged expeditiously in order to maximize the benefits of different modes of transport and transport nodes in terms of efficiency and environmental impact. The aim of the study is to analyze the problems of synchronized intermodal traffic management between the main port and inland transport nodes in European transport corridors and to find reliable solutions to these problems. Therefore, the main purpose of this article is to investigate the problem of the distribution of containers transported by rail between two transport terminals in a synchronous transport network. A specific optimization model is presented in this article. This optimization task is formulated as a stochastic integer programming model between the terminals located in Vilnius and Klaipeda Seaport, the essence of which is as follows: (a) to minimize the waiting time for container cargo at the location—terminal No. 1; (b) to minimize the total journey time of the train; (c) to minimize the waiting time for containerized cargo at the point of arrival—terminal No. 2.

scholarly journals Urban Rail Timetable Optimization to Improve Operational Efficiency with Flexible Routing Plans: A Nonlinear Integer Programming Model

2019 ◽  
Vol 11 (13) ◽  
pp. 3701 ◽  
Author(s):  
Qiuchi Xue ◽  
Xin Yang ◽  
Jianjun Wu ◽  
Huijun Sun ◽  
Haodong Yin ◽  
...  
Keyword(s):  
Integer Programming ◽  
Waiting Time ◽  
Optimization Model ◽  
Programming Model ◽  
Urban Rail Transit ◽  
Nonlinear Integer Programming ◽  
Load Factor ◽  
Integer Programming Model ◽  
Passenger Flow ◽  
Urban Rail

At present, most urban rail transit systems adopt an operation mode with a single long routing. The departure frequency is determined by the maximum section passenger flow. However, when the passenger flow varies greatly within different sections, this mode will lead to a low load factor in some sections, resulting in a waste of capacity. In view of this situation, this paper develops a nonlinear integer programming model to determine an optimal timetable with a balanced scheduling mode, where the wasted capacity at a constant departure frequency can be reduced with a slight increase in passenger waiting time. Then, we simplify the original model into a single-objective integer optimization model through normalization. A genetic algorithm is designed to find the optimal solution. Finally, a numerical example is presented based on real-world passenger and operation data from Beijing Metro Line 4. The results show that the double-routing optimization model can reduce wasted capacity by 9.5%, with a 4.5% increase in passenger waiting time, which illustrates the effectiveness of this optimization model.

Route selection for best distances in road databases based on drivers’ and customers’ preferences

2012 ◽  
Vol 42 (6) ◽  
pp. 1126-1140 ◽  
Author(s):  
P. Flisberg ◽  
B. Lidén ◽  
M. Rönnqvist ◽  
J. Selander
Keyword(s):  
Integer Programming ◽  
Shortest Path ◽  
Optimization Model ◽  
Programming Model ◽  
Mixed Integer ◽  
Route Selection ◽  
Speed Limits ◽  
Online System ◽  
Selection For ◽  
National Road

The importance of road databases for distance calculations and route selection is increasing. One reason is that payments and invoicing are often based on the distance driven. However, it can be hard to agree on a “best” distance because of drivers’ preferences. These preferences can be described by road features such as road length, quality, width, speed limits, etc. Moreover, a pure standard “shortest path”, which is often used in road databases, can result in a route that is considerably shorter than a preferred and agreed distance. Consequently, there is a need to find suitable weights for the features of the roads that provide fair and agreed distances at the same time for all users. We propose an approach to find values of such weights for the features. The optimization model to find weights is an inverse shortest path problem formulated in a mixed integer programming model. The approach is tested for the Swedish Forestry National Road database. Since 2010, it has been in daily use to establish distances and is available for all forestry companies and haulers in Sweden through an online system.

Equity and Strength in Stochastic Integer Programming Models for the Dynamic Single Airport Ground-Holding Problem

2020 ◽  
Vol 54 (4) ◽  
pp. 944-955 ◽  
Author(s):  
Alexander S. Estes ◽  
Michael O. Ball
Keyword(s):  
Integer Programming ◽  
Network Flow ◽  
Programming Model ◽  
Programming Models ◽  
Stochastic Integer Programming ◽  
Flow Problems ◽  
Proposed Model ◽  
Equity Property ◽  
Strong Formulation ◽  
Size Scales

We study stochastic integer programming models for assigning delays to flights that are destined for an airport whose capacity has been impacted by poor weather or some other exogenous factor. In the existing literature, empirical evidence seemed to suggest that a proposed integer programming model had a strong formulation, but no existing theoretical results explained the observation. We apply recent results concerning the polyhedra of stochastic network flow problems to explain the strength of the existing model, and we propose a model whose size scales better with the number of flights in the problem and that preserves the strength of the existing model. Computational results are provided that demonstrate the benefits of the proposed model. Finally, we define a type of equity property that is satisfied by both models.

scholarly journals Transfer Coordination for Metro Networks during the Start- or End-of-Service Period

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Liqiao Ning ◽  
Peng Zhao ◽  
Wenkai Xu ◽  
Ke Qiao
Keyword(s):  
Integer Programming ◽  
Adverse Effects ◽  
Waiting Time ◽  
Programming Model ◽  
Mixed Integer ◽  
Service Period ◽  
Proposed Model ◽  
Transfer Success ◽  
Metro Networks

When travelling via metro networks during the start- or end-of-service period, transferring passengers may suffer a transfer failure. Accordingly, the synchronization timetabling problem necessitates consideration of transfer waiting time and transfer availability with respect to the first or last train. Hence, transfer train index (TTI) is formulated to identify the transfer train and calculate the transfer waiting time. Furthermore, two types of connection indexes, the last connection train index (LCTI) and the first connection train index (FCTI), are devised to distinguish transfer failure from transfer success, and the penalty constraints are implemented together to reflect the adverse effects of transfer failure. Then, a mixed integer programming model is developed to concurrently reduce transfer waiting time and improve transfer availability, which can be solved by CPLEX. Finally, a case study on Beijing metro network is made to verify the method. Experimental results show that our proposed model can yield synchronization solutions with significant reductions in both the average transfer waiting time and the proportion of transfer failure passengers.

Modelling of sharing networks in the circular economy

2020 ◽  
Vol 15 (2) ◽  
pp. 407-440
Author(s):  
Jaivignesh Jayakumar ◽  
Jayakrishna K. ◽  
Vimal K.E.K. ◽  
Sawarni Hasibuan
Keyword(s):  
Mathematical Model ◽  
Environmental Impact ◽  
Circular Economy ◽  
Production System ◽  
Economic Benefit ◽  
Programming Model ◽  
Sharing Economy ◽  
Consumer Electronics ◽  
Mixed Integer ◽  
Content Type

Purpose The purpose of this paper is to develop and optimize a mathematical model based on a framework that integrates key concepts related to a circular economy (CE) and sharing economy (SE) for a leading manufacturer of laptops in India. Design/methodology/approach This study mathematically modelled the integration of sharing networks in a circular production system. This is done through an optimization package that deploys a multi-objective mixed-integer linear programming model. Findings This study evaluated the economic benefit and the environmental impact associated with the aforementioned integration in a production system. This study illustrated the inverse relationship between economic benefit and environmental impact and provided a set of solutions that can be used according to the case organizations goals, capacities and logistical capabilities. Research limitations/implications This study will aid similarly structured companies in adopting this approach to integrate sustainable practices in their production system. It also enumerated Industry 4.0 (I4.0) use-cases that can be used to effectively implement this mathematical model. Further research can be conducted using multiple companies in an inter-dependent network to maximize synergy. Practical implications This study will help to better understand the role of sharing networks in the circular economy model especially in the consumer electronics industry. Originality/value This study is the first of its kind to mathematically model the integration of aspects related to SE and CE. It also validates the aforementioned model using a numerical case-study and offers decision-support to key executives within the case organization.

scholarly journals Analysis of Drone Fleet Type and Quantity for Medical Package Distribution in Emergency System

2020 ◽  
Vol 4 (1) ◽  
pp. 12
Author(s):  
Yujie Jiang ◽  
Shizhong Ma ◽  
Shilong Zhu
Keyword(s):  
Puerto Rico ◽  
Integer Programming ◽  
Mixed Integer Programming ◽  
Optimization Model ◽  
Programming Model ◽  
Mixed Integer ◽  
Iso Standard ◽  
Multi Objective ◽  
Emergency Medical ◽  
Emergency System

In order to cope with the disasters caused by the worst hurricane in Puerto Rico in 2017, it is necessary to build an emergency system to reduce the losses. An emergency system should include the location of ISO standard dry cargo containers and the distribution of emergency medical packages. This paper discusses the distribution of emergency medical package. Based on the above location results of ISO standard dry cargo container, taking the demand of disaster areas not exceed its supply into consideration and considering the timeliness and weak economy, a multi-objective mixed integer programming model is constructed on the premise of minimum transportation time and cost. It is determined that the drone fleet consists of four B, one C and one F drones. Through the optimization model, the distribution plan of emergency medical packages is formulated.

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