scholarly journals Theoretical Foundation of the Control of Pollination by Hoverflies in a Greenhouse

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 167
Author(s):  
Francisco J. Fernández ◽  
József Garay ◽  
Tamás F. Móri ◽  
Villő Csiszár ◽  
Zoltán Varga ◽  
...  

We propose a conceptual model for pollination and fertilization of tomato flowers in greenhouses crops by hoverflies, when the maximal number of adult pollinators maintained by the crops is less than what is needed for an economically successful pollination in greenhouses. The model consists of a two-stage process for additional feeding of hoverfly to maintain the pollinator density at the economically desired level. First, with a stochastic model, we calculate the density of flies necessary for the economically successful pollination, determined according to the economically expected yield. Second, using a deterministic optimal control model, we find a minimum cost supplementary feeding strategy. In summary, we theoretically demonstrate, at the present stage of the research without validations in case studies, that optimal supplementary feeding can maintain the economically desired hoverfly density.

2017 ◽  
Vol 79 (4) ◽  
Author(s):  
Noryanti Nasir ◽  
Mohd Ismail Abd Aziz ◽  
Akbar Banitalebi

The increases of operational felling cost have prompted the oil palm industry to look at the current practices. The felling activity is considered as the main aspects to improve and maintain palm oil production through the provision of effective and agronomic practices. To support this success and achieve minimum cost of operation, this study aims to develop a time-invariant linear quadratic optimal control model for controlling the felling and harvest rate of the oil palm plantation. The proposed model involves two state variables which are biomass and crude oil. The optimal parameters for the model are estimated using a set of real data collected from Malaysian Palm Oil Board (MPOB). The study analyzes the solution of the resulting control problem within a limited time frame of 30 years and the results provide an optimal feedback control for the felling and harvest rates.


2011 ◽  
Vol 467-469 ◽  
pp. 1066-1071
Author(s):  
Zhong Xin Li ◽  
Ji Wei Guo ◽  
Ming Hong Gao ◽  
Hong Jiang

Taking the full-vehicle eight-freedom dynamic model of a type of bus as the simulation object , a new optimal control method is introduced. This method is based on the genetic algorithm, and the full-vehicle optimal control model is built in the MatLab. The weight matrix of the optimal control is optimized through the genetic algorithm; then the outcome is compared with the artificially-set optimal control simulation, which shows that the genetic-algorithm based optimal control presents better performance, thereby creating a smoother ride and improving the steering stability of the vehicle.


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