scholarly journals Automation of production programs by setting conditions of stabilization of the planned system

2021 ◽  
Vol 258 ◽  
pp. 09062
Author(s):  
Alexey Yurgaytis ◽  
Kamol Kamolov
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Formulation ◽  
Technological Problem ◽  
Problem Statement ◽  
Production Program ◽  
Construction Companies ◽  
Minimum Number ◽  
Labor Resources ◽  
Variable Problem ◽  
Graphic Interpretation

Formation of a production program is a time-consuming variable problem. To solve it, many conditions and constraints must be taken into account. Computer power allows one to quickly and accurately solve problems with many variables, unlike a person who relies on his intuition and experience. The following materials and methods were used: collection and analysis of data from construction companies of various sizes, mathematical modeling of the processes of distributing labor resources, graphic interpretation of information, computer modeling. The stages of the problem statement: description of the organizational and technological problem of distributing labor resources, mathematical formulation, modeling and algorithmization using well-known metaheuristic approaches. In the course of solving the problem, a genetic algorithm was used that allows one to quickly find solutions in equations with many variables. The following constraints were determined: deadlines, maximum and minimum number of workers at the facility, minimum number of transfer of resources, minimum involvement of a subcontractor. As a result, all the necessary mathematical models and initial data for the development of a computer program for the automated distribution of labor resources among the facilities of the production program of the construction and installation organization were obtained.

Modeling And Optimization Of The Construction Organization's Production Program

2020 ◽  
pp. 49-56
Keyword(s):  
Software Package ◽  
Target Function ◽  
Optimization Models ◽  
Labor Resource ◽  
Production Program ◽  
Construction Organizations ◽  
Source Data ◽  
Labor Resources ◽  
Construction Organization ◽  
Planning Production

In the article, the author considers the problems of complex algorithmization and systematization of approaches to optimizing the work plans of construction organizations (calendar plans) using various modern tools, including, for example, evolutionary algorithms for "conscious" enumeration of options for solving a target function from an array of possible constraints for a given nomenclature. Various typical schemes for modeling the processes of distribution of labor resources between objects of the production program are given, taking into account the array of source data. This data includes the possibility of using the material and technical supply base (delivery, storage, packaging) as a temporary container for placing the labor resource in case of released capacity, quantitative and qualification composition of the initial labor resource, the properties of the construction organization as a counterparty in the contract system with the customer of construction and installation works etc. A conceptual algorithm is formed that is the basis of the software package for operational harmonization of the production program ( work plans) in accordance with the loading of production units, the released capacities of labor resources and other conditions stipulated by the model. The application of the proposed algorithm is most convenient for a set of objects, which determines the relevance of its implementation in optimization models when planning production programs of building organizations that contain several objects distributed over a time scale.

Mathematical modeling of the supercooled steel ingot formation. Problem statement

2020 ◽  
Vol 229 (2-3) ◽  
pp. 495-500
Author(s):  
Julia Bazdyreva ◽  
Vyacheslav Bilousov ◽  
Fedor Nedopekin ◽  
Vitaliy Bondarenko ◽  
Viktor Bodriaha ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Steel Ingot ◽  
Problem Statement ◽  
Formation Problem

scholarly journals RESEARCH OF VIBRATION MACHINES DYNAMICS FOR PRODUCT SURFACES PROCESSING BY MATHEMATICAL MODELING

2020 ◽  
pp. 35-43
Author(s):  
Volodymyr Topilnytskyy ◽  
Yaroslav Kusyi ◽  
Dariya Rebot
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Surface Treatment ◽  
Lagrange Equation ◽  
The Body ◽  
Technological Problem ◽  
Surface Processing ◽  
Approximate Methods ◽  
Vibration Machine ◽  
Working Chamber

The article describes the methodology for the study of the dynamics of vibrating machines for surface processing of products by mathematical modeling, which is presented in four main stages. The first stage: analysis of classes of vibrating machines for surface treatment of products, choice of basic for solving the technological problem, project of a unified calculation scheme of the machine. The second stage: development of a nonlinear mathematical model for describing the dynamics of the vibration machine working body and its filling, development of elements of automated calculations of the machine. The third stage: the study of the influence of the parameters of the vibrating machine, product sets and tools (with their various combinations) on the factors of the intensity of products surface processing. The fourth stage: recommendations for choosing vibrating machine parameters and machining bodies that will maximize the processing performance of products with the selected intensity criterion. A mathematical model for describing the motion of a vibrating machine for surface treatment of articles by a set of unrelated bodies of small size is created. It has two unbalance units that generate oscillations of its working body and a spring suspension-mounting of the working chamber (container). The model is parametric and nonlinear, incorporating key dynamic, kinematic and geometric parameters of the vibrating machine in symbolic format. It is constructed by: descriptions of the plane-parallel movement of the mechanical system, the rotational motion of the material point and the body; second-order Lagrange equation; asymptotic (approximate) methods of nonlinear mechanics. With the help of the model it is possible: to describe the oscillatory movement of the working chamber (container) of the vibrating machine; to study the influence of the machine parameters on the efficiency of performance of the set technological task, the conditions of occurrence of non-stationary modes of operation of the vibrating machine and the ways of their regulation.

The Students–Professors Problem—The Reversal Error and Beyond

2021 ◽  
pp. 1-37
Author(s):  
Uffe Thomas Jankvist ◽  
Mogens Niss
Keyword(s):  
Mathematical Modeling ◽  
Mixed Methods ◽  
Empirical Study ◽  
Secondary Students ◽  
Mixed Methods Design ◽  
Problem Statement ◽  
Upper Secondary ◽  
Reversal Error ◽  
The Impact ◽  
Error Types

Abstract This paper first introduces and reviews the existing research on the well-known “students–professors (S/P) problem”, which was first formulated in 1979. Next, it presents an empirical study of Danish upper secondary students’ answers to two mathematical modeling versions of the S/P-problem; a mathematization version (296 students), and a de-mathematization version (658 students). Besides reproducing several previously reported findings, e.g., the so-called reversal error, the study identifies new error types not previously reported in the literature. The mathematical modeling perspective adopted, along with a mixed-methods design, give rise to new potential explanations of the reversal error as well as explanations of the new error types. Our study shows that interpreting the linguistic formulation of the S/P-problem statement is not only related to language but is intrinsically of a mathematical – and cognitive – nature as well. Altogether, there is still more to be said about the S/P-problem forty years after its emergence. The impact sheet to this article can be accessed at 10.6084/m9.figshare.16610104.

Formulation of “Stability Equations” and Derivation of New Constructions with Complete Systems of Design-formulae for Variable-speed Control Mechanisms

1953 ◽  
Vol 167 (1) ◽  
pp. 319-339
Author(s):  
M. S. Frenkel
Keyword(s):  
Nuclear Physics ◽  
Characteristic Curve ◽  
Mathematical Formulation ◽  
Control Mechanisms ◽  
Variable Speed ◽  
Speed Governor ◽  
Minimum Number ◽  
Order Of Magnitude ◽  
The Stability ◽  
Stable Characteristic

Requirements for stability are formulated mathematically and, through the “transformatory operations of mathematics”, yield a series of “stability equations” of ascending order which are generally applicable, for example to control mechanisms, electronics†, nuclear physics, etc. From these stability equations, the equation of the stable characteristic curve of a governor, and the differential equations of the oscillations of a governor-engine system, are derived. It emerges that the first part of the new oscillatory equation is identical with the whole of the differential equation in the literature to date (unchanged since Maxwell 1868)‡, while the important second part, which consists of terms of the same order of magnitude as the first part and which is the only one containing the equation of the stable characteristic curve, is lacking in literature. The stability equations classify all possible constructions of variable-speed governor according to “order of stability”, which signifies important operating properties. This classification accounts for the known shortcomings of conventional types. The stability equations, combined with the mathematical formulation of practical requirements (speed-adjustment with only one actuating motion, etc.), lead to new basic types of variable-speed governor, with complete systems of design equations. In addition to determining all unknown dimensions, this set of equations is important because it derives constructions of which the complexity increases with order of stability and, furthermore, a simple construction which provides any required high order of stability with the minimum number of adjustable components.

Blood flow of Carreau fluid in a tapered artery with mixed convection

2014 ◽  
Vol 07 (06) ◽  
pp. 1450068 ◽  
Author(s):  
Noreen Sher Akbar
Keyword(s):  
Mathematical Modeling ◽  
Mass Transfer ◽  
Blood Flow ◽  
Mathematical Formulation ◽  
Shearing Stress ◽  
Carreau Fluid ◽  
Modeling And Analysis ◽  
Tapered Artery ◽  
Impedance Wall ◽  
Parameters Of Interest

This research is concerned with the mathematical modeling and analysis of blood flow in a tapered artery with stenosis. The analysis has been carried out in the presence of heat and mass transfer. Constitutive equation of Carreau fluid has been invoked in the mathematical formulation. The representation of blood flow is considered through an axially non-symmetrical but radially symmetric stenosis. Symmetry of the distribution of the wall shearing stress and resistive impedance and their growth with the developing stenosis is given due attention. Solutions have been obtained for the velocity, temperature, concentration, resistance impedance, wall shear stress and shearing stress at the stenosis throat. Graphical illustrations associated with the tapered arteries namely converging, diverging and non-tapered arteries are examined for different parameters of interest. Streamlines have been plotted and discussed.

scholarly journals ECONOMIC AND MATHEMATICAL MODELING OF INVESTMENT ATTRACTIVENESS OF CONSTRUCTION ENTERPRISES IN THE SYSTEM OF STAKEHOLDER RELATIONS

2020 ◽  
Vol 6 (4) ◽  
pp. 56-65
Author(s):  
Volodymyr Velychko ◽  
Evgeniy Grytskov ◽  
Dmytriy Prunenko
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
External Control ◽  
Construction Enterprise ◽  
Stakeholder Relations ◽  
Construction Enterprises ◽  
Construction Companies ◽  
Quantitative Basis ◽  
Sound Management ◽  
The Impact

The relevance of the process of implementation of economic and mathematical model of investment attractiveness of the construction enterprise in the stakeholder relation system is proved. The results of the analysis of the theoretical provisions for determining investment attractiveness and stakeholders of construction enterprises are presented. An economic and mathematical model for the formation of stakeholder groups in the system of relations with construction enterprises is proposed. A system of information and analytical support for an integrated assessment of the level of stakeholder relations and investment attractiveness of construction enterprises has been formed, which creates the basis for economic and mathematical modeling. The directions, methods, and models for assessing investment attractiveness and the level of stakeholder relations of construction enterprises are proposed. The practical aspects of their implementation are determined. The results of economic and mathematical modeling of the investment attractiveness of construction enterprises in the system of stakeholder relations are presented. The subject of the research is the directions of formation and realization of economic and mathematical modeling of investment attractiveness of enterprises in the system of stakeholder relations. The formation of the research methodology is carried out on the basis of the theoretical and methodological platform for determining the investment attractiveness of enterprises and stakeholders that interact in the relevant field. In addition, a set of methods is used to conduct the study: analytical (to determine indicators of investment attractiveness); expert assessments (to determine the index of stakeholder relations); method of analysis of hierarchies (to assess the importance of the impact of stakeholders (customers of construction products; workers of construction enterprises; top management; managers of various levels of construction enterprises; owners of construction enterprises; government bodies influencing the formation and level of interaction of stakeholders with construction enterprises; public organizations influencing activities in construction and architecture; corporate governance bodies of construction enterprises; the bodies of internal and external control interacting in the construction industry; the competitors of construction enterprises; the suppliers of inventories interacting with construction enterprises; stakeholders interacting in the formation and use of spatial, urban, environmental information and creating investment attractiveness of construction enterprises; the design organizations; other stakeholders interacting with construction enterprises) at the level of stakeholders from noses of enterprises); economic and mathematical modeling (to establish causal links between the level of stakeholder relations and the index of investment attractiveness of enterprises); generalization and systematization (to obtain and interpret research results). The aim of the study is to establish causal relationships between the factors that shape the level of stakeholder relations and investment attractiveness of construction companies based on economic and mathematical tools. The result of the study is the formation of a quantitative basis for making sound management decisions in the system of stakeholder relations of construction companies to increase their investment attractiveness.

scholarly journals KEY AUDIT MATTERS PRACTICES IN CONSTRUCTION SECTOR: EVIDENCE OF MALAYSIAN MARKET

2020 ◽  
Vol 37 (01) ◽  
Author(s):  
UMMI JUNAIDDA HASHIM ◽  
NORSIAH AHMAD ◽  
WAN AMALINA WAN ABDULLAH ◽  
ZALAILAH SALLEH
Keyword(s):  
Listed Company ◽  
Successful Implementation ◽  
Construction Sector ◽  
Revenue Recognition ◽  
Construction Company ◽  
Construction Companies ◽  
Minimum Number ◽  
The Subject ◽  
One Year ◽  
High Uncertainty

This paper examines the reporting of Key Audit Matters (KAMs) in independent auditor‟s report for construction sector in the Malaysian market. It also aims to identify whether the specific characteristics of construction company will influence the KAMs reporting for Malaysian companies. The sample covers all construction companies listed on Bursa Malaysia with available data one year upon the implementation of KAMs. This business sector has been the subject of the study due to the fact that construction sector, despite being a high-risk sector, is among important sectors that contribute to the development of the economy of a country. The objective of the study is achieved through content analysis. The maximum and minimum number of KAMs disclosed are six and one respectively for this sector. The main issue addressed as KAMs in construction sector is revenue. The revenue recognition in the construction sector is affected by the unexpected occurrences and this, in turn, will affect the estimated cost and profit. The findings discover that the practice on the KAMs disclosed has been critically assessed by the auditors, but there is exception on some of the practice. In the construction sector, the items listed as KAMs basically relates to areas that required a significant amount of judgement from auditors (matters that involve high uncertainty estimation). However, for some of the KAMsdisclosure, 24% of the sample do not highlight the reason of why the items listed as KAMs. This circumstance would provide questions whether auditors had dismissed the guidelines of the disclosure of KAMs or auditors did not understand the KAMs‟ practices comprehensively. Therefore, further monitoring is needed to ensure the successful implementation of KAMs. This study only covers a limited sample of one year upon implementation of KAMs. It provides an empirical data and description on Key audit matters (KAMs) disclosure in the independent auditor‟s report of the Malaysian Listed company.

scholarly journals System of indicators for planning and evaluating production capacity of a construction and installation organization

2021 ◽  
Vol 258 ◽  
pp. 09053
Author(s):  
Ivan Abramov ◽  
Anastasia Martyanova
Keyword(s):  
Production Capacity ◽  
Production Program ◽  
Current State ◽  
Intensive Use ◽  
Actual Volume ◽  
Labor Resources ◽  
The One ◽  
Production Capacities ◽  
The Impact ◽  
The Relationship

To assess the production capacity of a construction and installation organization, the actual volume of work performed for a certain period and planned indicators for the use of certain resources are used. Since the state of production facilities depends not only on the production program, but also on the current state of labor resources, the actual task is to choose the most effective criteria for planning and evaluating the production capacity of a construction and installation organization. In formulating the criteria, the author was guided by the theory, allowing to establish the relationship between the production capacity of building-assembling organizations and production program and capabilities assessment and planning of production capacity for the coefficients of their extensive and intensive use. The study made it possible to form a system of indicators for planning and evaluating the production capacity of a construction and installation organization. The purpose of forming a system of indicators for planning and evaluating production capacities is to take into account in the calculations not only the actual and planned volumes of construction and installation works, but also indicators that reflect the current state of labor resources. The study revealed that through the formation of a system of evaluation indicators, taking into account the impact on production capacity of quantitative and qualitative factors expressed in the structure of labor resources, their qualifications on the one hand, as well as the rhythm and load of the construction and installation organization on the other hand.

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