scholarly journals An Application of Optimal Control to Sugarcane Harvesting in Thailand

Computation ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 36
Author(s):  
Wisanlaya Pornprakun ◽  
Surattana Sungnul ◽  
Chanakarn Kiataramkul ◽  
Elvin James Moore
Keyword(s):  
Optimal Control ◽  
Sugar Industry ◽  
Sugar Content ◽  
Optimization Methods ◽  
North Central ◽  
North East ◽  
Thai Government ◽  
The Government ◽  
Quasi Newton ◽  
Optimal Control Methods

The sugar industry is of great importance to the Thai economy. In general, the government sets sugarcane prices at the beginning of each harvesting season based on type (fresh or fired), sweetness (sugar content) and gross weight. The main aim of the present research is to use optimal control to find optimal sugarcane harvesting policies for fresh and fired sugarcane for the four sugarcane producing regions of Thailand, namely North, Central, East and North-east, for harvesting seasons 2012/13, 2013/14, 2014/15, 2017/18 and 2018/19. The optimality problem is to determine the harvesting policy which gives maximum profit to the farmers subject to constraints on the maximum amount that can be cut in each day, where a harvesting policy is defined as the amount of each type of sugarcane harvested and delivered to the sugar factories during each day of a harvesting season. The results from the optimal control methods are also compared with results from three optimization methods, namely bi-objective, linear programming and quasi-Newton. The results suggest that discrete optimal control is the most effective of the five methods considered. The data used in this paper were obtained from the Ministry of Industry and the Ministry of Agriculture and Co-operatives of the Royal Thai government.

scholarly journals Fast numerical design of spatial-selective rf pulses in MRI using Krotov and quasi-Newton based optimal control methods

2012 ◽  
Vol 137 (5) ◽  
pp. 054203 ◽  
Author(s):  
Mads S. Vinding ◽  
Ivan I. Maximov ◽  
Zdeněk Tošner ◽  
Niels Chr. Nielsen
Keyword(s):  
Optimal Control ◽  
Control Methods ◽  
Rf Pulses ◽  
Numerical Design ◽  
Quasi Newton ◽  
Optimal Control Methods

Optimal Control Methods for an Electrochemical Sewage

1996 ◽  
Vol 28 (1-2) ◽  
pp. 85-92
Author(s):  
Valentin V. Ostapenko ◽  
A. P. Yakovleva ◽  
I. S. Voznyuk ◽  
V. M. Rogov
Keyword(s):  
Optimal Control ◽  
Control Methods ◽  
Optimal Control Methods

scholarly journals An Optimal Control Problem by a Hybrid System of Hyperbolic and Ordinary Differential Equations

Games ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Alexander Arguchintsev ◽  
Vasilisa Poplevko
Keyword(s):  
Optimal Control ◽  
Differential Equations ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Ordinary Differential Equations ◽  
Hyperbolic Equations ◽  
Control Methods ◽  
The Right ◽  
The Cost ◽  
Optimal Control Methods

This paper deals with an optimal control problem for a linear system of first-order hyperbolic equations with a function on the right-hand side determined from controlled bilinear ordinary differential equations. These ordinary differential equations are linear with respect to state functions with controlled coefficients. Such problems arise in the simulation of some processes of chemical technology and population dynamics. Normally, general optimal control methods are used for these problems because of bilinear ordinary differential equations. In this paper, the problem is reduced to an optimal control problem for a system of ordinary differential equations. The reduction is based on non-classic exact increment formulas for the cost-functional. This treatment allows to use a number of efficient optimal control methods for the problem. An example illustrates the approach.

scholarly journals Optimal Control for a COVID-19 Model Accounting for Symptomatic and Asymptomatic

2020 ◽  
Vol 8 (1) ◽  
pp. 168-179
Author(s):  
Jead M. Macalisang ◽  
Mark L. Caay ◽  
Jayrold P. Arcede ◽  
Randy L. Caga-anan
Keyword(s):  
Optimal Control ◽  
Control Theory ◽  
Medical Care ◽  
Optimal Control Theory ◽  
Comparable Result ◽  
Type Model ◽  
Hospital Beds ◽  
Transmission Reduction ◽  
Bed Capacity ◽  
The Government

AbstractBuilding on an SEIR-type model of COVID-19 where the infecteds are further divided into symptomatic and asymptomatic, a system incorporating the various possible interventions is formulated. Interventions, also referred to as controls, include transmission reduction (e.g., lockdown, social distancing, barrier gestures); testing/isolation on the exposed, symptomatic and asymptomatic compartments; and medical controls such as enhancing patients’ medical care and increasing bed capacity. By considering the government’s capacity, the best strategies for implementing the controls were obtained using optimal control theory. Results show that, if all the controls are to be used, the more able the government is, the more it should implement transmission reduction, testing, and enhancing patients’ medical care without increasing hospital beds. However, if the government finds it very difficult to implement the controls for economic reasons, the best approach is to increase the hospital beds. Moreover, among the testing/isolation controls, testing/isolation in the exposed compartment is the least needed when there is significant transmission reduction control. Surprisingly, when there is no transmission reduction control, testing/isolation in the exposed should be optimal. Testing/isolation in the exposed could seemingly replace the transmission reduction control to yield a comparable result to that when the transmission reduction control is being implemented.

scholarly journals Development of an Optimal Start Control Strategy for a Variable Refrigerant Flow (VRF) System

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 271
Author(s):  
Yusung Lee ◽  
Woohyun Kim
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Predictive Performance ◽  
Building Energy ◽  
Data Driven ◽  
Energy Usage ◽  
Optimal Control Strategy ◽  
Save Energy ◽  
Time Required ◽  
Optimal Control Methods

In this study, an optimal control strategy for the variable refrigerant flow (VRF) system is developed using a data-driven model and on-site data to save the building energy. Three data-based models are developed to improve the on-site applicability. The presented models are used to determine the length of time required to bring each zone from its current temperature to the set point. The existing data are used to evaluate and validated the predictive performance of three data-based models. Experiments are conducted using three outdoor units and eight indoor units on site. The experimental test is performed to validate the performance of proposed optimal control by comparing between conventional and optimal control methods. Then, the ability to save energy wasted for maintaining temperature after temperature reaches the set points is evaluated through the comparison of energy usage. Given these results, 30.5% of energy is saved on average for each outdoor unit and the proposed optimal control strategy makes the zones comfortable.

Yakut Governor Ivan Kraft and His Contribution to the Construction of the Amur-Yakutsk Highway at the Beginning of the 20th Century

2021 ◽  
pp. 94-97
Author(s):  
Lev M. Dameshek ◽  
◽  
Margarita D. Kushnareva ◽  
Keyword(s):  
20Th Century ◽  
Russian Federation ◽  
Interdisciplinary Approach ◽  
Research Problem ◽  
Strategic Decision ◽  
Asia Pacific ◽  
East Siberia ◽  
North East ◽  
The Russian Federation ◽  
The Government

The article considers the activities of Ivan Kraft, the governor of Yakutsk Oblast, on the incorporation of North-East Siberia into the single economic, administrative and sociocultural space of the Russian Empire. The aim of the study is to analyze Kraft's contribution to the construction and arrangement of the Amur-Yakutsk Highway at the beginning of the 20th century. To reach this aim, the authors broadly use archival sources that have not been previously published and introduced into academic discourse. The topic has theoretical and applied relevance. It has not been sufficiently studied in the historiography of North-East Siberia and is the subject of scholarly and political discussions. The key method in the study is an interdisciplinary approach to the research problem, which is at the intersection of history and economics. The authors used content analysis for a quantitative and qualitative study of these sources based on the principle of historicism and consistency. The authors determined that, in connection with the design of the Amur Railway, the Amur-Yakutsk Highway received the status of a strategic infrastructure object in the macroregion. The authors note that Kraft was the initiator of the construction of the route from Yakutsk to the Amur. The governor conducted a number of scientific and engineering surveys of the most convenient route and made applications for financing the construction of the highway. Kraft made a strategic decision to attract private companies with large capital for the construction. The Upper Amur Gold Mining Company and the Heirs of A. I. Gromova company helped build highway sections with a total length of more than 500 km, equip stations, establish telegraph communications, and construct river crossings. At the beginning of the 20th century, in the framework of modernization measures, Kraft considered Yakutsk Oblast as a mining region. This became the basis for raising the question of Yakutia's access to the Trans-Siberian Railway. The close cooperation of the government, in the person of Kraft, with large enterprises of the region was the basis for the project of constructing a railway line to Yakutsk. In conclusion, the authors note that the processes of incorporation of the Asian borderlands of Russia into the economic, administrative and sociocultural space of the state that Governor of Yakutsk Oblast Ivan Kraft began at the beginning of the 20th century were reflected in the modern policy of the Russian Federation. The Amur-Yakutsk Mainline was put into operation in 2015. At present, the problem of building a bridge across the Lena in the Yakutsk area is still relevant. In 2019, President of the Russian Federation Vladimir Putin signed orders to begin the construction of the bridge. This will create an international transit corridor between Europe and the Asia-Pacific region.

scholarly journals Regional Differences in Postnatal Care Service Utilisation and Child Morbidity in Nigeria: Evidence from 2018 Nigeria Demographic and Health Survey (NDHS)

2020 ◽  
Author(s):  
Endurance Uzobo ◽  
Aboluwaji D. Ayinmoro
Keyword(s):  
Socioeconomic Factors ◽  
Health Survey ◽  
Postnatal Care ◽  
Demographic And Health Survey ◽  
The South ◽  
North Central ◽  
North West ◽  
North East ◽  
South West ◽  
Child Morbidity

Abstract Introduction: Modern Postnatal Care Services (PNC) in Nigeria is vital tool for providing quality health for mothers and newborns. Nonetheless, many regions in Nigeria are still struggling to achieve optimum utilisation of modern PNC services due to variation in associated socioeconomic factors of mothers based on their regions. This study aims at assessing regional socioeconomic factors associated with PNC services utilisation and its relationship with child morbidity in Nigeria. Methods Data for this study was extracted from the Nigeria Demographic and Health Survey (NDHS) 2018 birth recoded file dataset, with a sample size of 30713 women (aged 15–49). Data were analysed using descriptive statistics, Chi-Square Test and logistic regression. The main predictor variable was the region, while others included the type of PNC service utilised and various demographic variables of the respondents – age, education, type of residence, religion, ethnicity among others. Results The average age of the respondents was 29.5 ± 6.8. The use of modern PNC services ranged from South-West (20.3%), South-South (10.9%), South-East (23.0%), North-Central (22.0%), North-East (13.0%) to North-West (10.9%). The prevalence of child morbidity ranged from South-West (8.5%), South-South (9.8%), South-East (11.4%), North-Central (15.3%), North-East (26.3%) to North-West (28.7%). Child morbidity is significantly higher in the South-South (OR = 1.46), South-East (OR = 1.50), North-Central (OR = 1.13), North-East (OR = 2.31) and North-West (OR = 1.35) compared to the South-West. Conclusion Majority of women in Nigeria are not using modern PNC services. Regional variations in the use of PNC services and socio-demographic characteristics of mothers influence child morbidity in Nigeria. There is need for regional-specific context sensitisation for mothers in the use of modern PNC services.

scholarly journals Why Goat Farming in Northern Communal Areas of Namibia Is not Commercialised: The Case of Ogongo Constituency

2018 ◽  
Vol 11 (6) ◽  
pp. 236
Author(s):  
Cecil Togarepi ◽  
Benisiu Thomas ◽  
Namutenya Hilka Mika
Keyword(s):  
Household Head ◽  
Income Generation ◽  
Economic Potential ◽  
Formal Sector ◽  
North Central ◽  
Household Level ◽  
Head Of Household ◽  
Communal Areas ◽  
The Government ◽  
Goat Farming

In Namibia, goat products are not found in the formal markets include retail shops. This is despite several attempts by the government of Namibia to promote goat products in the formal sector. At household level however, goat meat is a delicacy. This study therefore seeks to provide possible reasons for the unavailability of goat products in Northern Namibia focussing on the supply side of the goat market. A structured survey questionnaire was employed among 75 goat farmers in Ogongo Constituency, Omusati Region in North Central Namibia. The data sought included production, offtake and marketing of goats as well as challenges faced. Descriptive statistics were used to analyse the data and multiple linear regression was employed to determine the factors influencing offtake rate. The offtake rate (percent of goats sold) was estimated as 2.8% from the data, which is very low. The offtake rate was significantly influenced by age of the head of household (p<0.01), education level of the household head (p<0.01) and marital status (p<0.01). On the other hand, goat production was affected by other challenges such as unavailability of marketing infrastructure, diseases, grazing shortages, and frequent droughts. The implications of these findings on policy include provision of incentives to farmers to sale as well as providing marketing infrastructure. Thus the study recommends the sensitization of communal farmers on economic potential of selling goats to alleviate poverty and to improve livelihoods through income generation.

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