14. Mathematical Models: A Stochastic Sequential Approach

1962 ◽  
pp. 540-562 ◽  
Keyword(s):  
Mathematical Models ◽  
Sequential Approach

Application of Response Surface Model for Sizing Solar Thermal Energy System at Residential Scale During the Early Design Stages

2020 ◽  
Author(s):  
Mohamed Hany Abokersh ◽  
Hatem Elayat ◽  
Mohamed Osman ◽  
Mohamed El-Morsi
Keyword(s):  
Mathematical Models ◽  
Thermal Performance ◽  
Desirability Function ◽  
Surface Model ◽  
Budget Constraints ◽  
Water Heating ◽  
Sequential Approach ◽  
Forced Circulation ◽  
Solar Water Heating ◽  
Solar Water

Abstract In the present study, the design of experiments (DOE) methodology is employed to statistically model and optimize the thermal performance of a forced circulation solar water heating system (FSWHS) with various budget constraints using a small number of simulation trails. The simulation trails are implemented using a model developed in TRNSYS 17 software, and climate conditions of Cairo, Egypt. A sequential approach is used to obtain the optimum system configuration with respect to the budget constraint. The definitive screening design is first utilized to eliminate the insignificant factors and investigate the effect of the quadratic terms. Then, the Box-Behnken design (BBD) is used for developing mathematical models based on multiple regression analysis. Finally, the optimization problem is formulated and solved using the desirability function. The developed mathematical models for the thermal performance responses showed a good agreement with the results obtained in TRNSYS for various budget constraints. This agreement proved the ability of the mathematical models to predict the performance of FSWHS precisely. Furthermore, the optimization methodology can be applied for various types of solar water heating systems, and different renewable energy applications.

Oral contraception by the sequential approach

JAMA ◽  
1966 ◽  
Vol 197 (12) ◽  
pp. 943-948 ◽  
Author(s):  
E. T. Tyler
Keyword(s):  
Oral Contraception ◽  
Sequential Approach

Handbook of Mathematical Models for Languages and Computation

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

Diagnostics, Optimization and Mathematical Models of Coke-Sinter-Hot Metal Production Process

2019 ◽  
Author(s):  
O. Lebid ◽  
Y. Vyshinskya ◽  
N. Gordon ◽  
V. Chaika ◽  
G. Izumskiy ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Production Process ◽  
Hot Metal ◽  
Metal Production

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.

Sign in / Sign up

Export Citation Format

Share Document