Multi-criteria Optimization Task Research Articles

Information System for Evaluation of Investments in the Field of Information Technologies

Creating an information system for evaluating investments in the field of information technology is a relevant task as it influences the efficiency of resource utilization in this strategically important sector. Information technologies are rapidly evolving, and proper investment evaluation can contribute to maximizing profitability and reducing risks. The research highlights various approaches to addressing this issue, each defined by its own characteristics. The study analyzes the investment process, proposing a mathematical model for investment problems in the form of a multi-criteria optimization task with Boolean variables. A structural approach is used to depict the principles of the system’s operation and information flows. Development tools are selected, and a prototype of the software is implemented. Further research directions include system verification and the development of additional modules to enhance functionality.

Optimalno rešenje nosača jednogredne mosne dizalice primenom algoritma Moljca

Introduction/purpose: The paper analyses and optimizes the welded I-girder of the single-beam bridge crane with a U-profile as the top flange. This solution is to provide a lighter carrying structure, so the main goal is to minimize the weight of the main girder, i.e., the cross-sectional area while fulfiling the requirements defined by national standards and geometric constraints. Methods: The Moth-Flame Optimization (MFO) algorithm was chosen for solving this single-objective multi-criteria optimization task using MATLAB. Also, the results were verified by using the Finite Element Analysis (FEA). Results: The proposed girder shape is justified in examples of real solutions of single-beam bridge cranes and the previous research results. In this case, significant savings in the material and better results are achieved compared to the examples from the previous research. Conclusion: The proposed girder shape, methodology, the optimization algorithm and the achieved savings fully justify this research. Furthermore, this algorithm enables the application of many constraint functions, whereby the optimal values of numerous variables are obtained in a relatively short period. Therefore, it would not be possible to find the solution for that engineering task by applying analytical optimization methods.

Multi-Criteria Optimization of Energy and Water Consumption in Fruit- and Vegetable-Processing Plants in Poland

Fruit and vegetable processing comes 6th in terms of energy consumption in the agri-food industry. At the same time, 88.4% of the industry’s final energy consumption structure is thermal energy, which depends heavily on electricity consumption. In addition, fruit and vegetable processing has a significant impact on the environment due to consumption of significant amounts of water. Reducing these three indicators simultaneously would increase the efficiency of the process while improving environmental protection. This paper proposes neural models of thermal energy, electricity and water consumption for selected major fruit- and vegetable-processing plants in Poland. These models were the basis for formulating a multi-criteria optimization task. Optimization of thermal energy, electricity and water consumption was carried out using genetic algorithms. The optimization results in the sense of Pareto can be the basis for the use of sustainable technology in selected fruit- and vegetable-processing plants.

Optimization methods for multi-criteria decisions in pharmacy

Optimization methods for multi-criteria decisions in pharmacy
 In pharmaceutical technological research, the determination of the quantitative composition of granules is considered as a task of multi-criteria selection. Today, to solve this problem, the regression analysis and multi-criteria optimization methods are widely used; they are based on mathematical models obtained for the object under study.
 Aim. To identify a decision-making method in a multi-criteria space that is effective for use in pharmaceutical technology research with quantitative factors.
 Materials and methods. The study uses tools of the popular computer mathematics system Mathcad (MathSoft Ins., USA) to automate the solution of mathematical problems. To automatically search for the type and coefficients of regression equations, the MS Excel application was used, namely: the data analysis package (regression analysis). The MS Word processor was used to edit the code.
 Results. A variety of approaches to the formalization of the multi-criteria optimization task have been studied. The optimal quantitative content of excipients when developing the granule technology has been found using two different optimization criteria, which are formed according to different methodical approaches. The method proposed does not provide for the mandatory introduction of gradation of individual criteria or their weighting factors.
 Conclusions. As a result of the comparison of multi-criteria optimization methods, the effectiveness of the decision-making method in the multi-criteria space has been shown; it synthesizes a mathematical procedure related to the vector of criteria and is based on determining the ideal point and introducing the concept of a norm into the space of functionals; it has not been mathematically proven, but it is practically useful decision-making algorithm compared to the mathematical method of convolution of criteria. The optimization method proposed has advantages that are manifested in the possibility of using a relatively simple mathematical apparatus and simplified logic of obtaining a solution.

Optimization of reinforced concrete beams under local mechanical and corrosive damage

ABSTRACT This article addresses the task of multicriteria optimization concerning the mechanical safety of reinforced concrete structures. New optimality criteria are formulated taking into consideration the relative risk of accidents arising as a result of natural disasters and human-induced impacts. An improved adapted genetic algorithm is developed as a basic search tool. It can be distinguished from the existing heuristic schemes by the following features. The algorithm can account for several possible accidents cenarios involving combinations of discrete or group impacts such as corrosive damage and local mechanical damage. The proposed optimization method incorporates multipoint variable operators that enable the convergence of the optimization procedure to increase by 40–60% and can effectively solve problems with a large number of variable parameters. The developed adapted genetic algorithm enables the implementation of multicriteria optimization with respect to nonlinear structural behaviour.

Application of bacterial optimization algorithms for selecting a site to construct a tank park on the main oil pipeline

The oil industry is the leading sector of the Russian economy, that makes the largest contribution to the country’s budget, creates a huge number of jobs and fully meets the domestic needs for oil and its products. In Russia, transportation of crude oil from fields to consumers (primarily refineries) is carried out by 5 modes of transport. Pipeline transport has received the greatest distribution. It provides transportation for 83% of crude oil and 30% of oil products. The most important element of the pipeline system is tank parks, which are used to collect and store oil at the junctions of technological pipeline sections and transshipment to other modes of transport. They are especially dangerous industrial objects. Therefore, they are subject to extremely stringent design and construction requirements. The most important stage in the construction of a tank park is the site selection, which is carried out on the basis of economic criteria and engineering requirements. In order to reduce the number of options for its location, where the survey party will travel, it is proposed to conduct a preliminary selection of the most promising territories by solving the task of multi-criteria optimization. The presence of a huge number of criteria leads to the need to use heuristic methods, among which swarm optimization algorithms based on modeling the collective behavior of various living organisms are widely used. To solve this problem, it is proposed to use bacterial optimization algorithms that allow taking into account both favorable and negative factors. Fuzzy logic elements can be added to the classical algorithm (it is proposed to set the initial positions of bacteria using fuzzy-logical inference systems, where the available statistics and expert assessments will be input parameters). In general, the proposed approach can be used to select sites for the construction of various hazardous industrial facilities, for which a large number of parameters must be taken into account.

Developing a Quasi-Optimal, in Terms of Transition Time and Energy Consumption, Closed-Loop Control System for an Electrical Installation

Introduction. The efficiency and normal work of electrotechnological processes and installations in their operation dynamic modes is characterized by the time of transition from initial to final state, low energy consumption, accuracy in transients and stability of the desired final state. It is proposed, from a single position on the basis of special optimal control, to combine transition and stabilization systems both in terms of determining the control algorithm with minimal energy consumption in the function of the object states and determining the parameters and conditions of movement with minimal deviation from a given trajectory providing the optimal transmission time and energy saving in a stable closed system of an object control. Materials and Methods. The principle of maximum is used as the main method for finding optimal program control, which for the study of special modes was supplemented with the apparatus of the position generality conditions for nonlinear objects with the coordinate space expansion, taking into account the occurrence of time and optimality criterion. The position generality apparatus is also used to solve energy-saving problems through using linearization in a large source object. Quasi-optimality in terms of transition time and energy consumption is achieved through minimizing energy according to the program motion parameter, which has a contradictory effect on the transition time and control amplitude. Results. To assess computational difficulties, transition time, energy saving, accuracy and stability, an example of inertial object control according to various criteria is given. The structure of a closed quasi-optimal system with stationary feedback, which is simple in technical implementation, is obtained. Discussion and Conclusion. The formalization of the approach to the construction of quasi-optimal systems based on the position generality allows it to be used in multi-criteria optimization tasks and computer-aided design systems for energy-intensive industrial, transport, and agricultural electrical installations.

Multi-criteria multi-stage game optimization

The article presents a mathematical model of a multi-stage game of the process of safe control of a transport object in possible collision situations with other encountered objects, containing a description of state variables, state and control constraints, and sets of permissible object strategies. Multi-criteria optimization tasks were formulated in the form of positional and matrix games under the conditions of playing non-cooperative and cooperative control as well as non-game optimal control. The multi-criteria control algorithms corresponding to these tasks were computer simulated in Matlab / Simulink on the example of a real situation.

Machine learning algorithms for the problem of optimizing the distribution of parcels in time-dependent networks: the case study

In the paper we present machine learning algorithms for the problem of optimizing the distribution of parcels in sto-chastic time-dependent networks, which have been built as a part of some Distribution Optimization System. The prob-lem solved was a modified VRPTW (Vehicle Routing Problem with Time Windows) with many warehouses, a heteroge-neous fleet, travel times depending on the time of departure (stochastic time-dependent network) and an extensive cost function as an optimization criterion. To solve the problem a modified simulated annealing (SATM) algorithm has been proposed. The paper presents the results of the algorithm learning process: the calibration of input parameters and the study of the impact of parameters on the quality of the solution (calculation time, transport cost function value) de-pending on the type of input data. The idea is to divide the input data into classes according to a proposed classifica-tion rule and to propose several strategies for selecting the optimal set of calibration parameters. These strategies consist in solving some multi-criteria optimization tasks in which four criterion functions are used: the length of the designated routes, the computation time, the number of epochs used in the algorithm, the number of designated routes. The subproblem was building a network model of travel times that is used in constructed SATM algorithm to determine the travel time between recipients, depending on the time of departure from the start location. An attempt has been made to verify the research hypothesis that the time between two points can be estimated with sufficient accuracy depending on their geographical location and the time of departure (without reference to the micro-scale, i.e. the detailed structure of the road network). The research was conducted on two types of data for Warsaw: from transport companies and one of the Internet traffic data providers. Learning the network model of travel times has produced very promising results, which will be described in the paper.

The Assessment of the Key Competences for Lifelong Learning—The Fuzzy Model Approach for Sustainable Education

Contemporary education in higher education institutions has a goal to provide necessary competences determined by legislative demands, science trends and job market needs to graduated students intending to strengthen their employability. The main idea of this research is to assess the level of students’ competences for lifelong learning (LLL). Since it is a very complex task, it is characterized by a lack of information and the vagueness of the inherently subjective nature of human thinking. The uncertain values of the assessed level of students’ competences for LLL are represented by linguistic expressions which are modeled by the interval type 2 trapezoidal fuzzy numbers. Ranking of the level of students’ competences for LLL is stated as a fuzzy multi-criteria optimization task. The aggregation of students’ opinions into unique marks is given by using the proposed fuzzy Delphi technique. The rank of students’ competences for LLL is given by using the proposed fuzzy Simple Additive Weighting (FSAW). The order of measures that should be delivered to improve students’ competences is based on the obtained rank. The model is tested and discussed on the real data collected from a significant sample of the students with a proposal of future directions of the research.

Higher Education in Russia: The Rise of Economic Dominance

Choosing a university is not an easy matter, and, as a rule, it is a task of multi-criteria optimization, and one of the weighty criteria is career prospects. At present, the children of those who themselves were applicants during the USSR collapse started to choose a university. At that time, it was believed that only elite universities (Moscow State University, MGIMO, etc.) would serve as a social lift to the most prestigious organizations of business, government, and science. In part, this can explain the almost total desire of modern school graduates to have a higher education, although often it is the desire of their parents. Using the example of the higher education market in Russia, the author examines the tendencies of universities’ concentration, their stratifiation into three levels with different institutional conditions and the dominance of the upper levels (alpha universities) over the lower ones (beta and gamma universities). The article analyses Russian alpha universities’ features against the background of a similar global hierarchy and identifies development trends for universities after the explosive introduction of distance learning technologies.

SOFTWARE AND MATHEMATICAL COMPLEX FOR MULTICRITERIAL OPTIMIZATION OF TURNING PARAMETERS ON HEAVY MACHINES

The issues of creation of a software-mathematical complex (SMC) for multicriteria optimization are considered in the work. One of the most promising ways to increase the efficiency of machining processes is the use of cutting tools with wear-resistant coatings, which are increasingly applied for semi-finishing and rough turning of heavy machinery parts. Objective: to increase the efficiency of machining processes on heavy lathes due to multi-criteria optimization of the parameters of the rough turning process and the parameters of the technological system. Object of study: the machining processes on heavy lathes for parts such as bodies of revolution weighing up to 20 tons. Subject of study: the relationship between the efficiency of rough turning operations on heavy lathes and the geometric and design parameters of the cutting tool. To increase the efficiency of turning on heavy lathes, a software and mathematical complex for multicriteria optimization of the technological process parameters and technological system of heavy lathes has been developed. SMC allows to adjust the values of the target optimization functions, as well as the parameters of generated neural networks and the genetic algorithm. To perform the task of multicriteria optimization of the parameters of the technological process of machining in SMC there is a possibility of setting the parameters of the tool (cutting plates), followed by formation and accumulation of the tool base and setting the parameters of the workpiece: specification of the material and of the cutting effort. Also for various parameters of technological transition a possibility to form the table of normative parameters is provided, by which training of a neural network will be made.

A Method of Selecting the Number of Coordinates of a Vector Criterion in a Polyoptimal Decision-Making Process

An important problem when formulating multicriteria optimization tasks is the selection of such a number of partial criteria that their meaning, number, and order correspond to the modeled decision situation. The paper proposes a method of selecting the number of criteria in polyoptimal decision-making process. The conditions of completeness, coherence, and nonredundancy that must be met by the vector criterion adopted for the assessment of the decision situation were discussed. Using these conditions, the principles of selecting the number of partial criteria in the vector criterion were specified, specifying the theorem on extending or reducing the scalar criterion. Using the formulated method, a vector quality criterion was selected for the task of controlling the movement of a sailing object. The method proposed in the work can be useful for modeling any decision-making situation in such issues as designing complex systems, controlling complex objects in conditions of uncertainty, and making decisions in other systems.

CALS conception for the educational program at the university in the study of metrology and other technical disciplines

The educational program at the university is designed taking into consideration the university wishes and the requirements of regulatory documents. The basis of the training program is the curriculum. It contains academic disciplines with the appropriate parameters: a semester, a number of credit units, the number of hours for classroom work, types of classes. For its implementation the resources are used: a lot of teachers (in departments), a lot of students (in groups), a lot of classrooms (for classes), a lot of equipment (of various types), a lot of training materials, a lot of e-learning courses. Many academic disciplines are combined with each set of resources. Each resource has its own parameters. To allocate the resources, these parameters and many conditions should be considered. This is a multi-criteria optimization task. The resource parameters and restrictions can change during the educational program’ functioning. It requires the development of a new educational program plan. This can be done using the concept of Continuous Acquisition and Life-Cycle Support (CALS) which is widely used in industry but not in education. The CALS concept is based on the use of automated information systems.

Formalizing Criteria of Intelligent Transportation and Logistic Systems Functioning

Modern intelligent transportation systems are complicated objects using adaptive control algorithms. These algorithms are based on sources of observation consisting of heterogeneous parameters describing functioning of the system, as well as retrospective information about the system behavior. The quality of management decisions depends on the good formulation of criteria for the functioning of the system and their optimal values. Criteria may have a different orientation: safety criteria, economic criteria, environmental criteria, etc. The need to take into account heterogeneous criteria leads to multicriteria optimization tasks. The paper presents approaches to formalize a multicriteria optimization for the functioning of transportation systems. Depending on the structure of the multicriteria optimization problem relevant algorithms for its solution are presented.

ALGORITHMS FOR MANAGING THE LOGICAL STRUCTURE OF THE DATABASE USING A PARAMETRIC MODEL OF COMPETITIVE ACCESS TO QUERIES BASED ON THE RANDOM FOREST METHOD

In article discusses the approach to development of mathematical software for support the process of managing the data schema in relational DBMS in terms of processing of parallel queries stream that compete for data in the hierarchy of the DBMS core memory. The necessity of the formation of a parametric model of queries competitive access. Briefly discusses methods of machine learning, allowing to solve the problem of regression recovery. The use of the random forest method as the most universal method of approximation of arbitrary functions is substantiated. A method of forming a parametric model of competitive access based on the random forest method, as well as an approach with the ensemble of sets of decision trees, which allows to provide the required generalizing ability and stability of the model to partial features and diversity of all types of queries received at the input of the DBMS. The stages of the developed algorithms are presented: ranking query parameters by total execution time and automatic data distribution, allowing you to go from approximating the target system with linear-continuous functions to a set of logical data schema objects, ordered by their effect on time, total query execution time, reducing multi-criteria optimization task to a task optimization by one criterion.

THE STATIC OPTIMIZATION TASK OF OPTIMAL DESIGN OF NONLINEAR ELECTRONIC SCHEME

The article deals with such an important selection of the elements of electronic scheme of the given configuration, when the certain requirements of technical task are satisfied and at the same time the selected optimality criteria reach the extreme value. The gives task has been solved by the method of one-criterion optimization, in particular, the method of center gravity. To formalize the given scheme we have compiled a mathematical model of optimization, which considers the requirements of technical task. The optimal design task of the presented electronic scheme was brought to the task of multi criteria optimization. The computational experiments have been resulted in the Pareto-optimal solutions, from which there was selected a compromise on that corresponds to the minimum capacity, required by the scheme. According to the optimal values of resistors, we have conducted a computerized analysis of the transient process of the given electronic scheme with the help of a computer program Electronics Workbench.

METHOD OF STRUCTURAL SYNTHESIS OF MANAGEMENT SYSTEM OF MEANS OF WATER TRANSPORT

The article presents the results of research on the ways of development of ship management systems. The analysis of operation shows that the most promising direction of co-development of these systems is their integration, integration and creation on the basis of such an association of "integrated bridging control systems by the ship". Also, the research of modern control systems suggests that the concept of their construction is based on the use of modernization of existing equipment in conjunction with new modern systems. Therefore, the task of multicriteria optimization of the structure of the control system according to known characteristics of existing subsystems of complexes is actual. The analysis of scientific and engineering approaches for the development and implementation of integrated bridging control systems has revealed a number of systemic deficiencies and remarks. Therefore, the scientific task is to improve existing and develop new models and methods for analyzing and synthesizing the ship management system based on a priori estimates of the technical efficiency of component subsystems. The analysis of the methods and approaches of compromising the solution in the solution of the multicriteria optimization problem, performed in the article, revealed a well-known method of successive concessions. This method most logically and effectively takes into account both the experience of the decision maker and the possibilities of analytical methods of one-criterion optimization. Also, in the article the features of the method of structural synthesis of the system of management of means of water transport improved by the authors, which unlike the existing ones, use the intellectualized approach of determining the assignment between efficiency and cost using parametric models of fuzzy expert conclusions based on neural networks. It is argued that the realization of the results obtained in the work allows to analyze the various variants of control systems, allows to carry out a comparative analysis and to determine the best value system according to the costeffectiveness criterion.

Expert control system of shipping operation on the Gabcikovo project

Task of shipping operations control of the Gabcikovo Project is to synchronize several requirements. These come from versatility of GAP and must meet with the following goals. The operation of GAP must be effective (maximization of the ship locks capacity, maximization of income from electricity production in hydropower plant); reliability of operation of the ship locks must not be limited or endangered by defects on technology parts of the ship locks caused by illegal parameters of water flow in the filling and emptying system; and shipping safety must not be endangered or limited by unsuitable parameters of river way (navigable depth below minimal shipping depths in ford sections caused by flow changes on Gabcikovo Project and ships crushing into riverbed of the Danube river). By taking these goals into account, it is possible, in general, to define operation of Gabcikovo Project as complex multi-criteria optimization task with many technological, water management, energetic and environmental constrains...

Analytical support for forming the strategy of export-import activity development of enterprises in Ukraine

The current economic situation in Ukraine is conditioned by the efficiency of the export-import activity of industrial enterprises. In turn, the effectiveness of the strategy for the development of this activity depends on the scientific substantiation of its analytical support. This confirms the relevance of the topic of the article. The purpose of the article is to present the content of analytical support for forming the strategy of development of export-import activity of the enterprises in Ukraine. The object of the study is the development of analytical support for the formation of this strategy. The main methods of developing this analytical support is the multicriterial optimization method, which uses a genetic algorithm, multidimensional regression analysis, and a taxonomic method for calculating the integral index of development. The article also examines the peculiarities of the implementation of export-import activity of industrial enterprises in modern conditions, analyzes the criteria for its development, provides a system of indicators for the evaluation of this activity and the setting of a multi-criteria optimization task of maximizing the development of export-import activity of the enterprise, the solution of which is recommended with the help of software MatLab. It is recommended that the optimal values obtained are taken as the basis for determining the desired values of the export-import performance indicators.