scholarly journals Optimization of regional transport networks based on a mathematical model of passenger preferences

2021 ◽  
Vol 2131 (3) ◽  
pp. 032101
Author(s):  
V V Kostenko ◽  
V A Golubtsov ◽  
R V Pank ◽  
A O Shmidt

Abstract This article presents the results of developing a model for a regional passenger transport network aimed at solving the logistical problem of constructing rational intermodal routes in a defined closed loop. The tools of graph theory and linear mathematical programming have been applied to build the model algorithm, which allows finding solutions for weighted graphs, in the absence of negative weight links, while keeping information about the sequence of hub points on the selected paths. The proposed solutions are versatile enough to be scalable for regions with different network topologies. The model is adapted to dynamically changing and extensible systems, allowing it to be practically applied to justify options for the future development of infrastructure in different modes of transport.

2015 ◽  
Vol 1 (1) ◽  
pp. 345-354 ◽  
Author(s):  
Emma Popa ◽  
Florian Ghionea

AbstractAt the level of premise, most experts agree that, in urban, traveling public wants so-called ex-ante demand do not get to be fulfilled by transmission system exploit, so-called ex post demand level is lower desires the reasons are complex, but the general idea is the network that descends satisfied offer between the two categories of demand. In this material is presented a mathematical model for evaluating the quality of urban transport networks, the proposed hierarchy is determinate by the post central level approach of ex- ante demand of ex -post ideal. The exploitation of urban passenger transport has led to a custom on improving service: It is believed that multiplying the number of routes or vehicles number will bring the ex post level to ex-ante levels. In this paper is demonstrated that this desideratum is impossible to achieve. Like conclusions: numerical values for ex-ante demand near to ex-post demand; a relatively simple instrument, but consistent, to prioritize urban transport networks; a procedure for determining the profitability of “breakthroughs” in constructive structure that would reduce the distance by setting the limit up to which may increase the fare.


2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Amirreza Hooshyar Telegraphi ◽  
Akif Asil Bulgak

AbstractDue to the stringent awareness toward the preservation and resuscitation of natural resources and the potential economic benefits, designing sustainable manufacturing enterprises has become a critical issue in recent years. This presents different challenges in coordinating the activities inside the manufacturing systems with the entire closed-loop supply chain. In this paper, a mixed-integer mathematical model for designing a hybrid-manufacturing-remanufacturing system in a closed-loop supply chain is presented. Noteworthy, the operational planning of a cellular hybrid manufacturing-remanufacturing system is coordinated with the tactical planning of a closed-loop supply chain. To improve the flexibility and reliability in the cellular hybrid manufacturing-remanufacturing system, alternative process routings and contingency process routings are considered. The mathematical model in this paper, to the best of our knowledge, is the first integrated model in the design of hybrid cellular manufacturing systems which considers main and contingency process routings as well as reliability of the manufacturing system.


2013 ◽  
Vol 436 ◽  
pp. 166-173
Author(s):  
A. Mihaela Mîţiu ◽  
Daniel Constantin Comeagă ◽  
Octavian G. Donţu

In this paper are presented some aspects of transmissibility control of mechanical systems with 1 DOF so that the effects of vibration on their action to be minimized. Some technical solutions that can be used for this purpose is analyzed. Starting from the mathematical model of an electro-mechanical system with 1 DOF, are identified the parameters which influence the effectiveness of the transmissibility control system using an electrodynamic actuator who work in "closed loop".


1973 ◽  
Vol 95 (2) ◽  
pp. 629-635 ◽  
Author(s):  
D. A. Smith ◽  
M. A. Chace ◽  
A. C. Rubens

This paper presents a detailed explanation of a technique for automatically generating a mathematical model for machinery systems. The process starts from a relatively small amount of input data and develops the information required to model a mechanical system with Lagrange’s equation. The technique uses elements of graph theory which were developed for electrical networks. The basic identifications required for mechanical systems are: paths from ground to mass centers, the independent loops of parts, if any, and paths associated with applied force effects. The techniques described in this paper have been used successfully in a generalized computer program, DAMN.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Saman Esmaeilian ◽  
Dariush Mohamadi ◽  
Majid Esmaelian ◽  
Mostafa Ebrahimpour

Purpose This paper aims to minimize the total carbon emissions and costs and also maximize the total social benefits. Design/methodology/approach The present study develops a mathematical model for a closed-loop supply chain network of perishable products so that considers the vital aspects of sustainability across the life cycle of the supply chain network. To evaluate carbon emissions, two different regulating policies are studied. Findings According to the obtained results, increasing the lifetime of the perishable products improves the incorporated objective function (IOF) in both the carbon cap-and-trade model and the model with a strict cap on carbon emission while the solving time increases in both models. Moreover, the computational efficiency of the carbon cap-and-trade model is higher than that of the model with a strict cap, but its value of the IOF is worse. Results indicate that efficient policies for carbon management will support planners to achieve sustainability in a cost-effectively manner. Originality/value This research proposes a mathematical model for the sustainable closed-loop supply chain of perishable products that applies the significant aspects of sustainability across the life cycle of the supply chain network. Regional economic value, regional development, unemployment rate and the number of job opportunities created in the regions are considered as the social dimension.


2021 ◽  
Author(s):  
Alessandro Zocca ◽  
Bert Zwart

Motivated by developments in renewable energy and smart grids, we formulate a stylized mathematical model of a transport network with stochastic load fluctuations. Using an affine control rule, we explore the trade-off between the number of controllable resources in a lossy transport network and the performance gain they yield in terms of expected power losses. Our results are explicit and reveal the interaction between the level of flexibility, the intrinsic load uncertainty, and the network structure.


2020 ◽  
pp. 2-18
Author(s):  
Dmitry Tali ◽  
◽  
Oleg Finko ◽  
◽  

The purpose of the research is to increase the level of security of electronic document metadata in the face of destructive influences from authorized users (insiders). Research methods: new scientific results allowed using a combination of data integrity control method based on the «write once» method and of authentication of HMAС messages (hash-based message authentication, as well as graph theory methods. Research result: a method of cryptographic recursive 2-D control of the integrity of electronic documents metadata is proposed. The analysis of the object of the study was carried out, based on the results of which it was concluded that it is necessary to effectively protect the metadata of electronic documents processed by automated information systems of electronic document management. Developed and described a mathematical model of the proposed method, based on graph theory. The developed technical solution makes it possible to implement the functions of cryptographic recursive twodimensional control of the integrity of the metadata of electronic documents, as well as to provide the possibility of localizing modified (with signs of violation of integrity) metadata records, in conditions of destructive influences of authorized users (insiders). This, in turn, reduces the likelihood of collusion between trusted parties by introducing mutual control over the results of their actions. The proposed solution makes it possible to ensure control of the integrity of data processed by departmental automated information systems of electronic document management, where, due to the peculiarities of their construction, it is impossible to effectively use the currently popular blockchain technology.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Filip Lorenz ◽  
Vit Janos ◽  
Dusan Teichmann ◽  
Michal Dorda

The article addresses creation of a mathematical model for a real problem regarding time coordination of periodic train connections operated on single-track lines. The individual train connections are dispatched with a predefined tact, and their arrivals at and departures to predefined railway stations (transfer nodes) need to be coordinated one another. In addition, because the train connections are operated on single-track lines, trains that pass each other in a predefined railway stations must be also coordinated. To optimize the process, mathematical programming methods are used. The presented article includes a mathematical model of the given task, and the proposed model is tested with real data. The calculation experiments were implemented using optimization software Xpress-IVE.


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