Browsing by Author "Essien, E."
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Item Decision support system for designing sustainable multi-stakeholder networks of grain storage facilities in developing countries(Computers and Electronics in Agriculture, 2018-04) Essien, E.; Dzisi, K.A.; Addo, A.Governments in developing countries often face the daunting task of designing a network of grain storage facilities to simultaneously benefit the various stakeholders (farmers, market traders, exporters, etc.) in the grain supply chain irrespective of the conflicting objectives of these stakeholders. Existing decision support systems either require data that are unavailable in most developing countries or have objectives irrelevant in the context of developing countries. This paper therefore develops a decision support system that integrates transportation, pseudo p-median, forecasting and goal programming models to optimally design networks of grain storage facilities to reduce the transportation cost of respective stakeholders. The effectiveness of the proposed decision support system has been demonstrated by comparing phantom networks developed with the decision support system to the Government of Ghana’s network of 48 grain storage facilities.Item Determining the Efficiency of the Government of Ghana’s Network of Grain Storage Facilities(West African Journal of Applied Ecology, 2018) Essien, E.; Addo, A.; Dzisi, K.A.Governments in developing countries design networks of grain storage facilities to help farmers store excess agricultural produce to prepare for climate induced crop failures. The efficiency of such networks has serious economic and food security implications on respective countries. Periodic review of the efficiency of such networks is necessary to identify lapses and opportunities for optimization. Past studies on efficiency of networks of facilities, which usually assume scenarios peculiar to the developed world used data that are usually unavailable or unreliable in developing countries. This work therefore developed an integrated approach that relies solely on readily available and reliable governmental and open source data to compute the short and long-term efficiencies of networks of grain storage facilities. This approach was used to analyze the efficiency of the government of Ghana’s network of forty-eight grain storage facilities. A transportation model was used to compute the total transportation cost within the existing network. A P-median model was then used to develop and compute the transportation cost of a theoretically optimal network. Outputs from a forecasting model were used with the transportation and P-median models to study the short and long-term efficiencies of the existing and optimal networks. The average short and long term efficiencies of the existing network were 66% and 26% respectively. The study also investigated the efficiencies of a rank network which is created by siting GSF’s in only high grain production districts. The short and long-term efficiencies of this network were 87% and 72% respectively. The study showed that Ghana’s GSFs were sub-optimally sited hence farmers would have to travel excessively longer distances than necessary to use it. This offers some explanation for its low patronage. Furthermore, the study shows that a rank network was not as efficient as the optimal network. This study therefore demonstrates the use of this integrated approach coupled with readily available data to analyze networks of grain storage facilities in developing countries.Item A Systematic Review of Linear Programming Techniques as Applied to Diet Optimisation and Opportunities for Improvement(Journal of Optimization, 2023) Donkor, L.; Essien, E.; Afrifah, N.S.Food provides the required nutrients for adequate growth and development. However, meeting the recommended nutrients while considering environmental sustainability can be complicated and challenging. Previously, trial-and-error methods were used for product development, but these are tedious and time-consuming. Mathematical techniques such as linear programming offer an alternative and rapid approach to developing products with nutritional and/or sustainability considerations. Tis method has been extensively used in diet optimisation but does not satisfactorily address dietary problems with more than one objective function. Aim. The review aimed to explore the extent of mathematical approaches to addressing dietary problems. Methodology. A systematic review approach was adopted for the research. The major search engines used were Scopus, PubMed, and and Science Direct, based on selected keywords. A stepwise structural method was used to obtain articles. Articles that contained The search keywords that were applied in nonhuman cases were excluded. Duplicated articles were also excluded and accounted for as one. All articles were subjected to further review based on their abstract and complete titles before passing them for data analysis. Results. The total number of articles obtained from the search activity was 280. Fifty-six were retained after the criteria for inclusion were applied to them. Out of the 56 articles retained, only two studies used goal programming and nonlinear generalised mathematical approaches to address dietary problems. All other studies used the linear programming approach, focusing mainly on one or two constraints (nutrients and/or acceptability), highlighting the limitations of linear programming in addressing the multiple factors of a sustainable diet. Several researchers have proposed using multiobjective optimisation, an extension of linear programming to address challenges with sustainable diets. These approaches can be further explored to address sustainable dietary problems.