Mathematical Models for Sustainable Inventory and Production Plans for Component Remanufacturing Problems of OEM with Break-Even Period Determination

2020 ◽  
pp. 75-132
Author(s):  
S. Malolan ◽  
M. Mathirajan
Keyword(s):  
Mathematical Models ◽  
Production Plans

scholarly journals Assessment of reserves and mathematical models of loading the active part of the main production funds of construction organizations

2020 ◽  
Author(s):  
Т.Г. Айгумов ◽  
В.Б. Мелехин
Keyword(s):  
Mathematical Models ◽  
Production Process ◽  
Active Part ◽  
Contract Work ◽  
Construction Organizations ◽  
Fixed Assets ◽  
Main Production ◽  
Under Construction ◽  
Production Plans ◽  
Internal Production

В работе предложены математические модели и методы, позволяющие эффективным образом реализовать в производственном процессе основные источники образования внутрипроизводственных резервов активной части основных производственных фондов в строительстве. Рассмотрена математическая модель массового обслуживания служащая для выявления условий обеспечивающих сокращение простоев активной части основных производственных фондов на основе роста доли времени их загрузки в общем объеме фонда рабочего времени. Разработана графоаналитическая модель и метод позволяющие определить оптимальные маршруты перемещения строительной техники по строящимся объектам и на этой основе повысить эффективность ее использования в процессе производства. Предложены оценки внутрипроизводственных резервов различного вида активной части основных производственных фондов с учетом их морального и физического износа, обеспечивающие возможность формирования напряженных производственных планов в целом и планирования объемов производства отдельного вида подрядных работ. Полученные результаты исследования позволяют повысить эффективность строительного производства и обеспечить его интенсивное развитие в современных условиях функционирования. The paper proposes mathematical models and methods that can effectively implement in the production process the main sources of formation of internal production reserves of the active part of fixed assets in construction. A mathematical model of queuing is considered, which serves to identify conditions that ensure a reduction in downtime of the active part of fixed assets based on the growth of the share of their load time in the total volume of the working time fund. A graphic-analytical model and method have been developed that allow determining the optimal routes for moving construction equipment along objects under construction and on this basis will increase the efficiency of its use in the production process. Estimates of internal production reserves of various types of the active part of fixed assets taking into account their moral and physical depreciation are proposed, providing the possibility of generating intense production plans in general and planning production volumes of a separate type of contract work. The results of the study can improve the efficiency of construction production and ensure its intensive development in modern conditions of operation.

Handbook of Mathematical Models for Languages and Computation

2019 ◽  
Author(s):  
Alexander Meduna ◽  
Petr Horacek ◽  
Martin Tomko
Keyword(s):  
Mathematical Models

Dependence of Current Harmonics of Greenhouse Irradiators on Supply Voltage

2020 ◽  
pp. 85-88 ◽  
Author(s):  
Nadezhda P. Kondratieva
Keyword(s):  
Mathematical Models ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Feasibility Studies ◽  
Power Losses ◽  
Voltage Level ◽  
Supply Networks ◽  
Current Harmonics ◽  
Cable Lines ◽  
Harmonic Composition

The article describes the results of the study concerning the effect of the voltage level on current harmonic composition in greenhouses irradiators. It is found that its change affects the level of current harmonics of all types of the studied greenhouse irradiators. With decrease of nominal supply voltage by 10 %, the total harmonic distortion THDi decreases by 9 % for emitters equipped with high pressure sodium lamps (HPSL), by 10 % for emitters with electrode-less lamps and by 3 % for LED based emitters. With increase of nominal supply voltage by 10 %, THDi increases by 23 % for lighting devices equipped with HPSL, by 10 % for irradiators with electrode-less lamps and by 3 % for LED based emitters. Therefore, changes of supply voltage cause the least effect on the level of current harmonics of LED based emitters and then the emitters with electrode-less lamps. Change of the level of supply voltage causes the greatest effect on the level of current harmonics of HPSL based irradiators. Mathematical models of dependence of THDi on the level of supply voltage for greenhouse emitters equipped with LED, electrode-less lamps and HPSL lamps were formulated. These mathematical models may be used for calculations of total current when selecting transformers and supply cable lines for greenhouse lighting devices, for design of new or reconstruction of existing irradiation systems of greenhouse facilities, and for calculation of power losses in power supply networks of greenhouse facilities during feasibility studies for energy saving and energy efficiency increasing projects.

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