scholarly journals SYSTEM ANALYSIS OF TECHNOLOGICAL PROCESSES

2021 ◽  
Vol 17 (4) ◽  
pp. 73-82
Author(s):  
Alexey Zhukov ◽  
Ekaterina Bobrova ◽  
Ivan Popov ◽  
Demissie Bekele Аrega
Keyword(s):  
System Analysis ◽  
Optimization Problems ◽  
Foam Glass ◽  
Algebraic Function ◽  
Mineral Wool ◽  
Polymer Concrete ◽  
Regression Equations ◽  
Technological Processes ◽  
Fine Grained ◽  
Cybernetic System

The article discusses ways to solve engineering problems in the study of technological processes using methods of system analysis. The essence of this method is to study the technology as a cybernetic system with an assessment of the" reactions” of this system to external influences formed during an active experiment. At the same time, optimization problems are solved analytically. Analytical optimization is based on two main principles. The regression equations obtained as a result of processing experimental data and testing statistical hypotheses are models that adequately describe real processes. Each of these equations is an algebraic function of several variables, to which methods of mathematical analysis are applicable, including the study of extremums of functions in partial derivatives. The next step is to develop a process algorithm and develop computer programs that allow you to select the composition and predict the properties of the product. As an engineering interpretation, it is possible to construct optimized nomograms that allow solving both direct and inverse problems; that is, predicting the result or selecting technological factors. The research methods described in the article are implemented in the study of technologies of cellular concrete, foam concrete, cement-polymer concrete and products made of mineral wool and foam glass. As an example, the article considers the optimization of the selection of the composition of fine-grained concrete reinforced with chopped glass fiber. The implementation of the developed method allowed us to determine the optimal value of the determining parameters, including the consumption of fiber and plasticizer, as well as to form a method for studying the properties of products.

scholarly journals Fine-grained concrete fibre-reinforced by secondary mineral wool raw material

2018 ◽  
Vol 1118 ◽  
pp. 012059 ◽  
Author(s):  
N P Gorlenko ◽  
Yu S Sarkisov ◽  
O V Demyanenko ◽  
N O Kopanitsa ◽  
E A Sorokina ◽  
...  
Keyword(s):  
Mineral Wool ◽  
Raw Material ◽  
Secondary Mineral ◽  
Fine Grained

A Strength Pareto Gravitational Search Algorithm for Multi-Objective Optimization Problems

2015 ◽  
Vol 29 (06) ◽  
pp. 1559010 ◽  
Author(s):  
Xiaohui Yuan ◽  
Zhihuan Chen ◽  
Yanbin Yuan ◽  
Yuehua Huang ◽  
Xiaopan Zhang
Keyword(s):  
Optimization Problems ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Population Diversity ◽  
Benchmark Problems ◽  
Multi Objective Optimization ◽  
Local Optima ◽  
Multi Objective ◽  
Fine Grained ◽  
Gravitational Search

A novel strength Pareto gravitational search algorithm (SPGSA) is proposed to solve multi-objective optimization problems. This SPGSA algorithm utilizes the strength Pareto concept to assign the fitness values for agents and uses a fine-grained elitism selection mechanism to keep the population diversity. Furthermore, the recombination operators are modeled in this approach to decrease the possibility of trapping in local optima. Experiments are conducted on a series of benchmark problems that are characterized by difficulties in local optimality, nonuniformity, and nonconvexity. The results show that the proposed SPGSA algorithm performs better in comparison with other related works. On the other hand, the effectiveness of two subtle means added to the GSA are verified, i.e. the fine-grained elitism selection and the use of SBX and PMO operators. Simulation results show that these measures not only improve the convergence ability of original GSA, but also preserve the population diversity adequately, which enables the SPGSA algorithm to have an excellent ability that keeps a desirable balance between the exploitation and exploration so as to accelerate the convergence speed to the true Pareto-optimal front.

Genetic Algorithms for Organizational Design and Inspired by Organizational Theory

2007 ◽  
pp. 412-428
Author(s):  
T. Yu
Keyword(s):  
Organizational Theory ◽  
Organizational Design ◽  
System Analysis ◽  
Optimization Problems ◽  
Clustering Method ◽  
Information Theoretic ◽  
Dependency Structure ◽  
Analysis And Design ◽  
Complex Engineering ◽  
Dependency Structure Matrix

Modularity is widely used in system analysis and design such as complex engineering products and their organization, and modularity is also the key to solving optimization problems efficiently via problem decomposition. We first discover modularity in a system and then leverage this knowledge to improve the performance of the system. In this chapter, we tackle both problems with the alliance of organizational theory and evolutionary computation. First, we cluster the dependency structure matrix (DSM) of a system using a simple genetic algorithm (GA) and an information theoretic-based metric. Then we design a better GA through the decomposition of the optimization problem using the proposed DSM clustering method.

scholarly journals Utilization of mineral wool waste and waste glass for synthesis of foam glass at low temperature

2019 ◽  
Vol 215 ◽  
pp. 623-632 ◽  
Author(s):  
Ru Ji ◽  
Yaxian Zheng ◽  
Zehui Zou ◽  
Ziwei Chen ◽  
Shen Wei ◽  
...  
Keyword(s):  
Low Temperature ◽  
Foam Glass ◽  
Mineral Wool ◽  
Waste Glass

scholarly journals Mathematical Apparatus for the Synthesis of Composite Materials with Specified Properties

2021 ◽  
Vol 1203 (2) ◽  
pp. 022011
Author(s):  
Eugenia Budylina ◽  
Irina Garkina ◽  
Alexander Danilov
Keyword(s):  
Composite Materials ◽  
Technological Process ◽  
Cognitive Modeling ◽  
System Analysis ◽  
Mechanical Characteristics ◽  
Extreme Values ◽  
Optimization Problems ◽  
Quality Criteria ◽  
Kinetic Processes ◽  
Physical And Mechanical Characteristics

Abstract The meaning of the creation and functioning of the system is defined as the achievement of extreme values of goals that unite the individual elements of the system into a single whole. Based on this, the main system attributes of composite materials are indicated. It is assumed that the systemic effect is generated by the systemic properties of quality criteria. The implementation of the technical task is initially determined at the stage of cognitive modeling with the establishment of intensive and extensive properties with the allocation of control parameters. Based on the cognitive map, hierarchical structures of quality criteria are determined, and in accordance with the selected quality criteria, the corresponding structural schemes of the system (for each selected scale level). Further, the system's quality criteria are formalized, and mathematical models are developed in accordance with each of the criteria. The main purpose of using system analysis is to apply the general principles of decomposition of the system into individual elements and establish connections between them, in determining the research goal and stages to achieve this goal (based on solving single-criterion optimization problems using the found optimal values). The formalization of the multicriteria problem and its solution are made based on the required operational values, the type of kinetic processes of the formation of the physical and mechanical characteristics of the material (determine its structure and properties). The problem of materials synthesis is reduced to the choice of the order and type of the differential equation; parametric identification within the chosen model; comparison of experimental and model kinetic processes at a given accuracy; adjusting the model (if necessary). Therefore, it is important to interpolate the kinetic processes of the formation of the main physical and mechanical characteristics of composite materials. The technological process is considered as a complex system consisting of elements of various levels of detail: from atomic to a separate process. Decomposition of the technological process consists in dividing it into basic operations (elements): preparation of materials, mixing of components, molding of a semi-finished product, heat treatment and additional operations. The effectiveness of this approach was confirmed in the development of chemically resistant sulfur composites, epoxy composites for radiation protection, etc. The initial prerequisite was the required operational values of the material and the type of kinetic processes. The results of effective use of interpolation models (including splines) of compressive strength, heat release, and shrinkage of composite epoxy materials are presented.

System Analysis of the State of Automation of Technological Processes for Cleaning Used Oils

2018 ◽  
Vol 22 (5) ◽  
pp. 54-58
Author(s):  
O.M. Gorbacheva ◽  
A.S. Borovsky
Keyword(s):  
Technological Process ◽  
System Analysis ◽  
Technical System ◽  
Waste Oil ◽  
Technological Processes ◽  
Used Oil ◽  
Functional Models ◽  
Oil Purification ◽  
Technical Systems ◽  
Degree Of Purification

Based on the system analysis using IDF0 diagrams, functional models of existing technical systems for cleaning used oil have been constructed. The influence of the parameters of the technological process on the time of its flow and the degree of purification of the used oil are described. After studying the influence of the parameters of the technological process of cleaning used oil and analyzing the existing automated technical oil purification systems, the necessity of developing a new automated technical system for cleaning the waste oil is substantiated, in which the parameters of the process that have not been considered previously will be monitored.

scholarly journals Modification of fine-grained polymer concrete with microsilica

2018 ◽  
Vol 212 ◽  
pp. 01010
Author(s):  
Vadim Balabanov ◽  
Ksenia Putsenko
Keyword(s):  
Building Materials ◽  
New Technologies ◽  
Import Substitution ◽  
Research Work ◽  
Scientific Research ◽  
Physical And Mechanical Properties ◽  
Polymer Concrete ◽  
Labor Costs ◽  
Modifying Additives ◽  
Fine Grained

At present, one of the most promising areas in construction is the modification of concrete by means of a complex of modifying additives and production wastes that will allow to obtain concrete with improved technical and operational characteristics and solve a number of problems: import substitution and nanotechnology. The aim of scientific research is the development of new technologies for obtaining concrete with enhanced performance characteristics, provided that raw materials, energy and labor costs are minimized. The article presents the results of research work on the development of fine-grained polymer concrete, modified with microsilica. In the framework of the study, a literature review for the last 68 years has been conducted, devoted to the experience of using microsilica and polymers in concrete construction as a modifier for building materials. The main characteristics of the starting materials and modifying additives are determined. A study was conducted to determine the effect of various modifying additives on the physicomechanical characteristics of fine-grained concrete. The main rheological properties and strength characteristics of the entire spectrum of the investigated compositions are determined. A microscopic study of the structure was carried out. The result of scientific research is the establishment of an optimal combination of additives, the development of cement concrete with the use of microsilica and acrylic dispersion and the determination of the effect of additives on the physical and mechanical properties.

Convex underestimating relaxation techniques for nonconvex polynomial programming problems: computational overview

2015 ◽  
Vol 24 (3-4) ◽  
pp. 129-143
Author(s):  
André A. Keller
Keyword(s):  
System Analysis ◽  
Convex Set ◽  
Optimization Problems ◽  
Convex Relaxation ◽  
Engineering Application ◽  
Global Optimum ◽  
Linear Matrix ◽  
Quadratic Term ◽  
Relaxation Techniques ◽  
Convex Envelopes

AbstractThis paper introduces constructing convex-relaxed programs for nonconvex optimization problems. Branch-and-bound algorithms are convex-relaxation-based techniques. The convex envelopes are important, as they represent the uniformly best convex underestimators for nonconvex polynomials over some region. The reformulation-linearization technique (RLT) generates linear programming (LP) relaxations of a quadratic problem. RLT operates in two steps: a reformulation step and a linearization (or convexification) step. In the reformulation phase, the constraint and bound inequalities are replaced by new numerous pairwise products of the constraints. In the linearization phase, each distinct quadratic term is replaced by a single new RLT variable. This RLT process produces an LP relaxation. The LP-RLT yieds a lower bound on the global minimum. LMI formulations (linear matrix inequalities) have been proposed to treat efficiently with nonconvex sets. An LMI is equivalent to a system of polynomial inequalities. A semialgebraic convex set describes the system. The feasible sets are spectrahedra with curved faces, contrary to the LP case with polyhedra. Successive LMI relaxations of increasing size yield the global optimum. Nonlinear inequalities are converted to an LMI form using Schur complements. Optimizing a nonconvex polynomial is equivalent to the LP over a convex set. Engineering application interests include system analysis, control theory, combinatorial optimization, statistics, and structural design optimization.

scholarly journals Optimal Safety System Design Using Fault Tree Analysis

1994 ◽  
Vol 208 (2) ◽  
pp. 123-131 ◽  
Author(s):  
J D Andrews
Keyword(s):  
System Analysis ◽  
Optimization Problems ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Design Parameters ◽  
Tree Analysis ◽  
Final Design ◽  
Current Design ◽  
Voting System ◽  
Implicit And Explicit

This paper describes a design optimization scheme for systems that require a high likelihood of functioning on demand. The final design specification is achieved by solving a sequence of optimization problems. Each of these problems is defined by assuming some form of the objective function and specifying a sub-region of the design space over which this function will be representative of the system unavailability. An example of a high-pressure protection system has been used to demonstrate the practicality of the technique. Design parameters for this system include redundancy levels, the number of elements required for a voting system to function, component selection options and maintenance inspection intervals. Both implicit and explicit constraint forms have been used in the example. The implicit constraints require a full system analysis to determine whether the current design is feasible or not. All system assessments have been carried out using fault tree analysis.

Improving Net Joint Torque Calculations Through a Two-Step Optimization Method for Estimating Body Segment Parameters

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Raziel Riemer ◽  
Elizabeth T. Hsiao-Wecksler
Keyword(s):  
Inverse Dynamics ◽  
Optimization Problems ◽  
Joint Torque ◽  
Optimization Approach ◽  
Regression Equations ◽  
Random Errors ◽  
Body Segment ◽  
Joint Torques ◽  
Body Segment Parameters ◽  
True Values

Two main sources of error in inverse dynamics based calculations of net joint torques are inaccuracies in segmental motions and estimates of anthropometric body segment parameters (BSPs). Methods for estimating BSP (i.e., segmental moment of inertia, mass, and center of mass location) have been previously proposed; however, these methods are limited due to low accuracies, cumbersome use, need for expensive medical equipment, and∕or sensitivity of performance. This paper proposes a method for improving the accuracy of calculated net joint torques by optimizing for subject-specific BSP in the presence of characteristic and random errors in motion data measurements. A two-step optimization approach based on solving constrained nonlinear optimization problems was used. This approach minimized the differences between known ground reaction forces (GRFs), such as those measured by a force plate, and the GRF calculated via a top-down inverse dynamics approach. In step 1, a series of short calibration motions was used to compute first approximations of optimized segment motions and BSP for each motion. In step 2, refined optimal BSPs were derived from a combination of these motion profiles. We assessed the efficacy of this approach using a set of reference motions in which the true values for the BSP, segment motion, GRF, and net joint torques were known. To imitate real-world data, we introduced various noise conditions on the true motion and BSP data. We compared the root mean squared errors in calculated net joint torques relative to the true values due to the optimal BSP versus traditionally-derived BSP (from anthropometric tables derived from regression equations) and found that the optimized BSP reduced the error by 77%. These results suggest that errors in calculated net joint torques due to traditionally-derived BSP estimates could be reduced substantially using this optimization approach.

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