scholarly journals Mathematical experiment as a tool for modeling the freight transportation process

2021 ◽  
Vol 2131 (2) ◽  
pp. 022094
Author(s):  
V A Bogachev ◽  
A S Kravets ◽  
T V Bogachev
Keyword(s):  
Computer Algebra System ◽  
Optimization Problem ◽  
Freight Transportation ◽  
Point Of View ◽  
Nonlinear Integer Programming ◽  
Integer Programming Problem ◽  
Mathematical Experiment ◽  
Balance Of Interests ◽  
Transportation Process ◽  
Welfare Theory

Abstract The process of multimodal freight transportation on a railway loop is investigated, for which a multicriteria optimization model with time indicators is created, which is a nonlinear integer programming problem. The developed approach is based on egalitarian and utilitarian principles in the welfare theory and allows (along with Pareto optimal transportation plans) to find other plans that can be considered rational from the point of view of maintaining the balance of interests of the transportation process participants. A mathematical experiment is an effective heuristic tool in research. The algorithm for solving the optimization problem is implemented in the environment of a computer algebra system and brought to numerical results.

scholarly journals USING THE METHOD OF SEQUENTIAL RESTRICTIONS FOR SOLVING A DUAL-OBJECTIVE PROBLEM OF PRODUCTION PLANNING

2020 ◽  
Vol 11 (87) ◽  
Author(s):  
Nataliia Dovha ◽  
◽  
Hryhorii Tsehelyk ◽  
Keyword(s):  
Optimization Problem ◽  
Production Efficiency ◽  
Point Of View ◽  
Main Task ◽  
Production Plan ◽  
Optimal Production ◽  
Economic Point ◽  
Use Of Resources ◽  
Maximum Profit

The processes of optimization of the production plan according to certain criteria by modeling were investigated. Achieving effective results directly depends on the optimal production plan. The most important thing in determining the optimal production plan is the choice of modeling criteria. For the most part, the quality of decisions is characterized not by one but by many incomparable criteria. Therefore, it is necessary to make decisions based not on one but on many criteria. This so-called multi-objective optimization problem. For solving such problems is widely used mathematical methods. Mathematical approach can be used to solve problems in any particular activity as mathematics abstracted from specific features characteristic of a particular solution. Therefore, from the point of view of mathematics, the optimal result can be obtained with various established criteria, but from the economic point of view it is important to choose the ones that are of decisive importance. That is, their weight is important for the consumer when making a purchase decision, and for the manufacturer – in terms of production capabilities of certain types and results (production efficiency). The basis of the operation of any enterprise is a production program (production and sales plan). The main task of the production plan is to meet the needs of consumers in high-quality products, which are produced with the best use of resources, on the one hand, and the enterprise to get the maximum profit, on the other. With this in mind, a two-criteria optimization model that allows to make a production plan was proposed. The plan ensures that products are produced with the best use of available resources and at the same time ensures maximum quality of manufactured products and maximum profit from sales of these products. The solution of the problem with two objective functions and linear constraints is achieved by step-by-step solution of the proposed mathematical model of optimization of the production plan using the method of sequential restrictions. The simplex method was also used. An example shows an algorithm for solving the optimization problem.

scholarly journals New Dzungaria Gates for wmlt-corridor: historical necessity

2019 ◽  
Vol 5 (3) ◽  
pp. 36-44
Author(s):  
Viktor A. Bogachev ◽  
Yuri A. Terentyev ◽  
Viktor V. Koledov ◽  
Taras V. Bogachev
Keyword(s):  
Mathematical Models ◽  
Variational Methods ◽  
High Speed ◽  
Optimization Problem ◽  
Point Of View ◽  
The North ◽  
Computer Math ◽  
Pass Through ◽  
Historical Necessity ◽  
North Western

Background: Research is ongoing relating to the analysis of a set of issues that arise in connection with the creation of the operating on the basis of vacuum magnetic technologies a transcontinental high-speed land transport corridor, connecting the eastern regions of China with Russia. As part of the variation calculus task, the geopolitical, economic, social, logistic, geographic, geomorphological, seismological, topographic components of the project are considered, in which it is assumed that the high speed overland route will pass through the north-western part of the historical region of Dzungaria. Aim: Find the most optimal from the point of view of the above components the location of the most important section of high speed overland route passing through Central Asia. Methods: Variational methods for solving an optimization problem with the use of a computer math system. Results: After creating a fairly informative and versatile picture of the region in question, the foundations of the corresponding mathematical models are built. Conclusion: The New Dzungarian Gates is a key element in choosing the location of a high-speed overland route based on VMLT.

scholarly journals Building reaction kinetic models for amiloid fibril growth

BIOMATH ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 1607311 ◽  
Author(s):  
Svetoslav Marinov Markov
Keyword(s):  
Computer Algebra ◽  
Computer Algebra System ◽  
Reaction Kinetic ◽  
Growth Models ◽  
Reaction Network ◽  
Network Models ◽  
Point Of View ◽  
Logistic Growth ◽  
Sigmoidal Functions ◽  
Methodological Aspects

In this work we  discuss some methodological aspects of the creation and formulation of mathematical  models describing the growth of species from the point of view of reaction kinetics. Our discussion is based on familiar examples of growth models such as logistic growth and enzyme kinetics. We   propose several reaction network  models  for  the amiloid fibrillation processes in the citoplasm. The solutions of the models are sigmoidal functions graphically visualized using  the computer algebra system   Mathematica.

scholarly journals Bi-Level Operation Scheduling of Distribution Systems with Multi-Microgrids Considering Uncertainties

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1441
Author(s):  
Saeid Esmaeili ◽  
Amjad Anvari-Moghaddam ◽  
Erfan Azimi ◽  
Alireza Nateghi ◽  
João P. S. Catalão
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Optimization Problem ◽  
Point Of View ◽  
Mixed Integer ◽  
Wholesale Market ◽  
System Operator ◽  
Level Model ◽  
Upper Level ◽  
Operation Scheduling

A bi-level operation scheduling of distribution system operator (DSO) and multi-microgrids (MMGs) considering both the wholesale market and retail market is presented in this paper. To this end, the upper-level optimization problem minimizes the total costs from DSO’s point of view, while the profits of microgrids (MGs) are maximized in the lower-level optimization problem. Besides, a scenario-based stochastic programming framework using the heuristic moment matching (HMM) method is developed to tackle the uncertain nature of the problem. In this regard, the HMM technique is employed to model the scenario matrix with a reduced number of scenarios, which is effectively suitable to achieve the correlations among uncertainties. In order to solve the proposed non-linear bi-level model, Karush–Kuhn–Tucker (KKT) optimality conditions and linearization techniques are employed to transform the bi-level problem into a single-level mixed-integer linear programming (MILP) optimization problem. The effectiveness of the proposed model is demonstrated on a real-test MMG system.

Operation Planning of District Heating and Cooling Plants Considering Contract Violation Penalties

2009 ◽  
Vol 13 (3) ◽  
pp. 185-192
Author(s):  
Kosuke Kato ◽  
◽  
Masatoshi Sakawa ◽  
Keiichi Ishimaru ◽  
Satoshi Ushiro ◽  
...  
Keyword(s):  
Cold Water ◽  
District Heating ◽  
Nonlinear Integer Programming ◽  
Planning Problem ◽  
Integer Programming Problem ◽  
Operation Planning ◽  
Urban District ◽  
Water Steam ◽  
Heating And Cooling ◽  
Contract Violation

Urban district heating and cooling (DHC) systems operate large freezers, heat exchangers, and boilers to stably and economically supply hot and cold water, steam, etc., based on customer demand. We formulate an operation-planning problem as a nonlinear integer programming problem for an actual DHC plant. To reflect actual decision making appropriately, we incorporate contract-violation penalties into the running cost consisting of fuel and arrangements expenses. We, then, solve operation-planning problems with and without penalties, demonstrating the effectiveness of taking penalties into consideration.

Can Lean eliminate waste in urban logistics? A field study

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Matias Escuder ◽  
Martin Tanco ◽  
Andres Muñoz-Villamizar ◽  
Javier Santos
Keyword(s):  
Point Of View ◽  
Lean Thinking ◽  
Content Type ◽  
Lean Principles ◽  
Lean Practices ◽  
The People ◽  
Transportation Process ◽  
The Subject ◽  
The City ◽  
Practical Implications

PurposeUrban logistics presents a series of challenges, as the interests of the different stakeholders are not always aligned. The aim of this research is to explore the potential of applying Lean principles to reduce waste in urban logistics.Design/methodology/approachAs a structure for “going to gemba,” the authors implemented the shadowing technique to better understand the perspective of companies distributing products in the city of Montevideo, Uruguay. Then, meetings were conducted to validate the observations by the people shadowed.FindingsThe results show that most of shipper's time is dedicated to waiting (59%), which is followed by driving (22%), and only a small section of time was dedicated to unloading and verification activities (19%). Although collaborative solutions are needed along with the different stakeholders, this research highlights how deploying Lean thinking can improve significantly urban logistics achieving up to 25% improvement in the number of stores served per shift.Practical implicationsFrom an academic point of view, this study emphasizes the importance of continue applying and evaluating the Lean practices into transportation contexts. From a company's perspective, the authors have presented a list of propositions that can be implemented for carriers in order to reduce waste and/or improve the efficiency of the urban transportation process.Originality/valueBased on the literature review carried out, the subject study of Lean and its application to urban logistics remains mostly unexplored in the scientific literature.

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