Multipurpose Optimization Research Articles

Determination of the relationship between the Los Angeles abrasion values of aggregates and concrete strength using the Response Surface Methodology

The present study aims to determine the relationship between aggregate abrasion strength and concrete strength considering water-to-cement and aggregate-to-cement ratios. For this purpose, concrete mixtures with different water-to-cement ratios (0.38, 0.40, 0.42, 0.45, 0.50, 0.55 and 0.60) were prepared with different aggregate types (basalt, marble, limestone, and natural aggregates). Hardened concrete properties of the prepared specimens were determined. Also, the abrasion tests were performed for each aggregate used in the experiments to determine the Los Angeles abrasion values of the aggregates. Using the experimental data, the compressive strength and splitting tensile strength values of the concrete specimens with dimensionless parameters such as water-to-cement ratio, aggregate-to-cement ratio, and Los Angeles abrasion loss value were analyzed using the Response Surface Methodology. Thus, two new models were developed with a multi-purpose optimization method. The compressive strength and splitting tensile strength can be calculated with high accuracy for different mixture designs with these models using the aggregate abrasion loss value, water-to-cement ratio, and aggregate-to-cement ratio. In conclusion, savings in labor and time, and economic profit are expected by designing a concrete mixture in this way.

Advanced “Confident Judgments” Method when Choosing Multicriteria Solutions in a Multipurpose Approach

The article considers the problem of making multicriteria decisions in which the decision maker (DM) has the opportunity to indicate the range of selection policies to determine the most effective scope of the considered alternatives. The concept of the Dirichlet area of an alternative is introduced in the blurred area of the target settings of the DM, and four groups of quantitative characteristics are proposed for a holistic description of these areas. A six-step decision-making algorithm is developed. Two mathematical models of multipurpose optimization and systematization of selection policies in the Dirichlet domain are proposed. The proposed method is illustrated by solving the problem of choosing the complex of the most rational concepts of a high-altitude unmanned aerial vehicle.

Improvement of the method of calculating a group of sound­insulating panels

Original single-layer and multilayer structures of sound-insulating panels are considered, as well as their advantages compared to traditional analogs. The shortcomings of the method of optimization calculation of a group of sound-insulating panels designed to reduce noise in several production rooms are analyzed. This method has limited functionality due to a relatively small number of objective functions and the corresponding conditions for their use. Given this, an improved method of optimization calculation of a group of sound-insulating panels is proposed. The improvement of the method consists in increasing the number of objective functions intended for multipurpose optimization taking into account real production conditions. The refinement of the algorithm consists in the preliminary selection of a subgroup of panels with additional requirements for operating conditions (increased strength, fire safety, etc.). Under these conditions, the operator directionally distributes structures and materials among the selected panels. The statement of the optimization problem of group calculation with an extended list of objective functions and restrictions is given. Recommendations on selecting an objective function in specific production conditions are given. The regulatory requirements for noise reduction in production rooms and spectral characteristics of sound insulation of panels made of various materials are given. The spectral characteristics of noise in the room before and after application of the sound-insulating panel are also given. The effectiveness of the method is confirmed by the steady reduction of the mathematical expectation and variance of the total noise load on people in production premises with an increase in the number of iterations. The calculation method demonstrated the reduction of excess noise load in comparison with standard methods

Numerical simulation of the catalytic process of isomerization of pentane-hexane cut

The basic schemes for the transformation of the pentane-hexane fraction catalytic isomerization, which are probable from the point of view of thermodynamics, have been considered. Based on the literary analysis of possible transformation schemes, the mechanism of the process and on the basis of experimental data, a mathematical model of the reactor block of the process was constructed and the kinetic parameters were determined. The foundations were laid for the subsequent solution of the tasks of the multi-purpose optimization of the catalytic isomerization process of the pentane-hexane fraction.

Исследование подходов к оценке экономической безопасности региона

The purpose of this article is the systematization and critical analysis of existing approaches to assessing the economic security of the region. The author reveals the advantages and disadvantages of theoretical and methodological concepts of the regional economic security assessment presented in the works of domestic and foreign scientists, as well as the system of indicators of economic security of the relevant strategy of the Russian Federation. Based on the results of the study, it is proposed to build a methodology for the analysis of regional economic security of Russian regions on the basis of the synthesis of economic and statistical methods, in particular, multi-purpose optimization, and subjective methods (discourse analysis). The main directions of improvement of the method of assessment of economic security of the Russian Federation established in the corresponding Strategy are defined. The article is of interest to representatives of federal and regional authorities, economists specializing in theoretical and regional issues.

Automated identification system of conditions for homogeneous and heterogeneous reactions in multipurpose optimization problems

Automated identification system of conditions for homogeneous and heterogeneous reactions in multipurpose optimization problems

M-generalization for multipurpose transactional data publication

Transactional data collection and sharing currently face the challenge of how to prevent information leakage and protect data from privacy breaches while maintaining high-quality data utilities. Data anonymization methods such as perturbation, generalization, and suppression have been proposed for privacy protection. However, many of these methods incur excessive information loss and cannot satisfy multipurpose utility requirements. In this paper, we propose a multidimensional generalization method to provide multipurpose optimization when anonymizing transactional data in order to offer better data utility for different applications. Our methodology uses bipartite graphs with generalizing attribute, grouping item and perturbing outlier. Experiments on real-life datasets are performed and show that our solution considerably improves data utility compared to existing algorithms.

A Survey on Securing and Optimizing Health Care Bigdata

Huge amount of health care data are available online to improve the overall performance of health care system. Since this huge health care Big-data is valuable and sensitive, it requires safety. In this paper we analyze numerous ways in which the health care Big-data can be protected. In recent days many augmented security algorithm that are suitable for Big-data have emerged like, El-Gamal, Triple-DES, and Homomorphic algorithms. Also authentication and access control can be implemented over Big-data using Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC) schemes.Along with security to Big-data we try to evolve the ways in which the valuable Big-data can be optimized to improve the Big-data analysis. Mathematical optimization techniques such as simple and multi-purpose optimization and simulation are employed in Big-data to maximize the patient satisfaction and usage of doctor’s consulting facility. And also, to minimize the cost spent by patient and energy wasted.

Self-adaptive multi-purpose Grey Wolf optimization for efficient routing of wireless ad hoc networks

One of the well-known issues in the field of network routing is the Shortest Path Routing (SPR). The objective is to find the least-cost path with minimum delay and link breaks. Even though there are many algorithms to solve SPR, the cost, as well as link breaks, are indeed more thought-provoking in the real-time application. This paper intends to develop a routing approach that solves the challenges like route establishment and route recovery. The selection of the optimal route is done by adopting a generalized multi-purpose optimization algorithm named Grey Wolf Optimizer. Along with this, this paper adopts Neural Network (NN) to predict the node movements in the ad hoc network. The proposed routing algorithm is compared to the conventional approaches, and the significance of the approach is described clearly.

Sliding Mode Control for PMSG-based Wind Power System

Variable structure control has proven particularly suitable to variable speed wind energy conversion system control, being easy to implement by the already existing electronics. Its main drawback is an increase of mechanical stress due to chattering, which can however be alleviated by various methods. This paper proposes a sliding mode approach for tracking the energetic optimum of a variable speed permanent magnet synchronous generator PMSG. The sliding surface is systematically derived from imposing a desired reduced-order dynamics and allows the turbine operation more or less close to the optimal regimes characteristic, according to an imposed trade-off between the torque (control input) ripple and the optimum tracking. In this way, by torque controlling the generator, a multipurpose (energy-reliability) optimization is actually achieved.

Métodos multicriterio aplicados en la selección de un material para discos de freno

La selección de material para un componente automotor es un proceso complejo, porque implica una exploración de los principales criterios de acuerdo con las propiedades exigidas por el componente a diseñar. El presente estudio tiene como objetivo evaluar un material alterno en la fabricación de un disco de freno en vehículos livianos tipo SUV, a partir de los métodos multicriterio; para lo cual se toman en consideración cinco materiales candidatos para la aplicación deseada (Ti6Al4V, Al10Si C, AISI 304L, ASTM A 536 y ASTM A48). Los métodos multicriterio (MCDM) empleados son: VIKOR – la optimización multidisciplinar y solución de compromiso; ELECTRE I – eliminación y opciones que reflejan la realidad; COPRAS – evaluación compleja proporcional; ARAS – evaluación de relación de aditivos; MOORA – optimización multiobjetivo basado en el análisis de radios y el método ENTROPÍA que se emplea para la ponderación de los criterios. Se obtiene que la mejor alternativa es el material ASTM A536 según los métodos COPRAS, ELECTRE I, y ARAS por su baja densidad, un alto límite elástico y una buena resistencia a la compresión; en segunda opción es el ASTM A48 según VIKOR y MOORA.

Method for Household Refrigerators Efficiency Increasing

The relevance of working processes parameters optimization in air conditioning systems is proved in the work. The research is performed with the use of the simulation modeling method. The parameters optimization criteria are considered, the analysis of target functions is given while the key factors of technical and economic optimization are considered in the article. The search for the optimal solution at multi-purpose optimization of the system is made by finding out the minimum of the dual-target vector created by the Pareto method of linear and weight compromises from target functions of the total capital costs and total operating costs. The tasks are solved in the MathCAD environment. The research results show that the values of technical and economic parameters of air conditioning systems in the areas relating to the optimum solutions’ areas manifest considerable deviations from the minimum values. At the same time, the tendencies for significant growth in deviations take place at removal of technical parameters from the optimal values of both the capital investments and operating costs. The production and operation of conditioners with the parameters which are considerably deviating from the optimal values will lead to the increase of material and power costs. The research allows one to establish the borders of the area of the optimal values for technical and economic parameters at air conditioning systems’ design.

APPLICATION OF A NOVEL THERMO-ECOLOGICAL PERFORMANCE CRITERION: EFFECTIVE ECOLOGICAL POWER DENSITY (EFECPOD) TO A JOULE-BRAYTON CYCLE (JBC) TURBINE

This study presents an application of a new performance analysis criterion named as Effective Ecological Power Density (EFECPOD) to a Joule-Brayton cycle (JBC) turbine. The turbine performance is expressed a single value by the proposed criterion using effective efficiency, effective power, cycle temperature ratio and volume. NOx formation and turbine dimensions are considered by the cycle temperature ratio and turbine volume, respectively. The turbine volume is also related to production cost of the heat engine. Therefore, the proposed criterion is essential for multi purpose optimization. Furthermore, this criterion can be developed and applied to the other gas cycle and heat engines. Also, the influences of engine design parameters such as cycle temperature ratio, pressure ratio, turbine speed, and equivalence ratio on the EFECPOD have been examined based on Finite-Time Thermodynamics Modelling (FTTM). In order to obtain realistic results, temperature-dependent specific heats for working fluid have been used and heat transfer and exhaust output losses have been taken into consideration. The results presented could be an essential tool for JBC turbine designers.

OPTIMIZATION OF THE MODE OF A POWER SUPPLY SYSTEM BY METHOD OF THEGREATEST GUARANTEED RESULT

At limited or untimely supply by fuel of power stations of a power supply system the deviation of actual modes of operation from planned is observed. In this case on some power stations deficiency of fuel takes place. Then at correction of a mode on the nearest interval of time in dispatching service of a power supply system assessments of admissible expenses of fuel on hard-to-get power stations should be passed. Thus, under direction of a problem of optimum distribution of active capacities rigid restrictions on admissible expenses of fuel are imposed and to provide a possibility of an output of actual expenses of fuel on not difficult to receive stations for earlier limits established. In this case transition from rigid restrictions on admissible expenses of fuel at not hard-to-get stations to indistinct restrictions is carried out. Now a problem expediently to state as a problem of multi-purpose optimization in which at an appropriate choice of functions of an accessory of indistinct sets it is possible to receive the satisfactory decision with a guarantee.

Multi-Disciplinary System Design Optimization of a Launch Vehicle Upper-Stage

The design method presented in this paper is related to the upper-stage system and its instrumentation, expedition and facilitation so as to transfer the satellite from the destination orbit to the target orbit. We used an integrated design method with a structure based on multidisciplinary system design optimization and developed a simple systematic interference method for designing aerospace products. The subsystems’ convergence in an optimized environment, matrix relationship, and integration of the subsystems’ parameters and presentation of design give results while meeting all requirements and considering the limitations of the design were the main aims of the research. Instead of a merely mathematical optimization design, in the present study a new design method with a systematic multipurpose optimization approach was designed. In this context, the optimization means the parameters are optimized as a result of the design convergence coefficients. Validation of the design method was not only obtained through comparison with a specific product but also with the systematic parameters of all upper-stage systems with a similar operation through the results of statistical design graphs. The approximate similarities of the results indicate an acceptable and genuine design with a quite systematic approach which is better than an unreal and merely optimized design.

Thermo-ecological performance analysis of a Joule-Brayton cycle (JBC) turbine with considerations of heat transfer losses and temperature-dependent specific heats

This study presents a new performance analysis criterion called Effective Ecological Power Density (EFECPOD) and its application to a Joule-Brayton cycle (JBC) turbine. Effective efficiency (EE), effective power (EP), cycle temperature ratio and turbine volume are considered together and the performance is stated a unique value by the developed criterion. emissions formation and turbine dimensions are considered by the cycle temperature ratio and turbine volume, respectively. The turbine volume is also related to production cost of the heat engine. Therefore, the proposed criterion is essential for multipurpose optimization. Furthermore, this criterion can be developed and applied to the other gas cycles and heat engines. Also, a performance investigation for the JBC gas turbine in terms of EE, EP and effective power density (EPD) has been carried out using a new finite-time thermodynamics modeling (FTTM). The influences of engine design parameters such as cycle temperature ratio, cycle pressure ratio, turbine speed, intake temperature, intake pressure and equivalence ratio on the EE, EP, EPD and EFECPOD have been examined. The results presented can be an essential tool for JBC turbine designers.

Efficiency of using cables on 6-110 kV with sticked polyethylene isolation

The expediency of using more expensive 6-10 kV cables with XLPE insulation was proved by us on the basis of the method of multi-purpose optimization, which took into account both the resulted costs for the construction and operation of cable lines, and the reliability of its operation, as well as the convenience of installation. Without compensation of capacitive currents, permissible difference in the height of the cable laying, the effect of cable lines on the environment.

Meta-optimization of populations algorithms in multipurpose optimization

Meta-optimization of populations algorithms in multipurpose optimization

A hybrid finite element analysis and evolutionary computation method for the design of lightweight lattice components with optimized strut diameter

Components incorporating lattice structures have become very popular lately due to their lightweight nature and the flexibility that additive manufacturing offers with respect to their fabrication. However, design optimization of lattice components has been addressed so far either with empirical approaches or with the use of topology optimization methodologies. An optimization approach utilizing multi-purpose optimization algorithms has not been proposed yet. This paper presents a novel user-friendly method for the design optimization of lattice components towards weight minimization, which combines finite element analysis and evolutionary computation. The proposed method utilizes the cell homogenization technique in order to reduce the computational cost of the finite element analysis and a genetic algorithm in order to search for the most lightweight lattice configuration. A bracket consisting of both solid and lattice regions is used as a case study in order to demonstrate the validity and effectiveness of the method, with the results showing that its weight is reduced by 13.5 % when using lattice structures. A discussion about the efficiency and the implications of the proposed approach is presented.

The complex systems parameters mathematical modeling and optimization by global connectivity in CAD

The design problems arising in multi-purpose optimization of systems with weakly bound arguments were analyzed. A classification of constraints on optimization arguments was done. The concept of "global connectivity" as interparametric limitation affecting virtually all the design and consumer properties of the system was introduced. Method of the global connectivity system optimization was developed on example of electrical equipment, which test provided a positive technical effect