Industrial Engineering and Logistic management
Permanent URI for this collectionhttps://etd.hu.edu.et/handle/123456789/75
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Item STREAM FLOW AND SEDIMENT YIELD MODELING: THE CASE OF ROBI JIDA WATERSHED, UPPER BLUE NILE BASIN, ETHIOPIA(Hawassa University, 2024-12-24) BELSTI DEGU NURIESoil erosion, streamflow, and sediment studies are crucial for supporting the agricultural sector through watershed planning and management practices. This study aimed to model stream flow and sediment yield in the Robi Jida watershed in the Upper Blue Nile Basin, Ethiopia, and identify best management scenarios with the records of suspended sediment concentration. The historical records of the meteorological, hydrological, and suspended sediment concentration data were used for the hydrological modeling. Sediment yield data was generated from the discharge-sediment rating curve equation using the suspended sediment concentration data. Spatially, 30*30 m DEM, 90*90m soil, and 30*30m resolution land use/land cover data were used as input for the hydrological model. In this study, the Soil and Water Assessment Tool (SWAT) model was used to model streamflow and sediment yield. The model performance in simulating streamflow and sediment yield was evaluated through sensitivity analysis, calibration, and validation processes. Period from 1994 to 2010 was used for calibration and 2011 to 2018 was used for validation. During calibration the model performance statics R2 , NSE, and PBIAS were obtained (0.80, 0.70), (0.80, 0.70), and (-4.8, 1.1) for stream flow and sediment yield respectively, and similarly for model validation R 2 , NSE, PBIAS as obtained (0.77, 0.72), (0.77, 0.71), (-4.7, -5.7) respectively. Therefore, the result indicated that the SWAT model performed well and the estimated average annual sediment yield of the Robi Jida watershed was 6.42 tons/ha/year. Based on the average annual simulated sediment yield, identified 9 sub-watersheds are critical whose annual sediment yield limit ranges above the tolerable limit were identified and prioritized for effective watershed management. Therefore applying and evaluating the different management scenarios, filter stripe 1m and 5m, vegetative contour strip, soil/stone bund, terracing, and contouring resulted in a 19.15%, 35.01%, 47.13%, 57.09%, 73.37%, and 52.81% decrease in the average annual sediment yield, respectively. Therefore, soil/stone bund and terracing scenarios demonstrated the highest potential for reducing sediment yield and showed promising results as effective best management practices in the Robi Jida watershed.Item OPTIMIZATION OF PROCESS PARAMETER BY USING SIMULATION- TAGUCHI APPROACH: A CASE OF HABTAMU SILA PLASTIC FACTORY IN HAWASSA CITY(Hawassa University, 2021-10-22) ADEME SISAY HAILEThe control of integrated manufacturing systems is usually complex. One approach that can accommodate such complexity is modeling the manufacturing processes on a computer. The primary objective of any company is to produce products with low cost. Process parameter optimization in a cost bases optimal selection of extrusion rate, setup time, feed rate, and capacity of the loading station. Besides, the use of computer simulation have been proposed and executed to tackle the issues of manufacturing cost reduction. A simulation model is an instrument in analyzing execution. Even though next studies of the outcomes of simulation can be used for investigation of design of experiment, investigation of optimum manufacturing process parameter to reduce the cost of manufacturing. Therefore, this paper deals with the optimization of process parameters in a manufacturing system to minimize the Unit Manufacturing Cost (UMC) of Un-plasticized Poly Vinyl Chloride pipes using a combined Simulation–Taguchi approach. With the new perspectives of integrated modeling, the study contributes to the body of knowledge, which also opens a new outlook for further studies. Taguchi design of experiment is useful for managing this study and L27 orthogonal array was selected. Thus, a significant factor along with their optimum combination is using Taguchi techniques to arrive at the least manufacturing cost. The results show that these methods can be useful in reducing the number of experimental trials needed to determine the best operating parameters. The results show that key parameters for optimum performance of the system are feed rate in to the hopper and the optimization of the extruder; The predicted unit cost of manufacturing the selected pipe model is 220 Birr and thus costs decreased by 28.8%., because the utilization of the machine increased by 33%, 34.6% for the worker from the actual performance. As part of the general outcome of this study, Taguchi method was helpful for reduction of unit manufacturing cost either at the product development or at process design stage and identifying optimum control parameter combinationsItem OPTIMIZATION OF PROCESS PARAMETER BY USING SIMULATION- TAGUCHI APPROACH: A CASE OF HABTAMU SILA PLASTIC FACTORY IN HAWASSA CITY(Hawassa Unversity, 2021-10-06) ADEME SISAY HAILEThe control of integrated manufacturing systems is usually complex. One approach that can accommodate such complexity is modeling the manufacturing processes on a computer. The primary objective of any company is to produce products with low cost. Process parameter optimization in a cost bases optimal selection of extrusion rate, setup time, feed rate, and capacity of the loading station. Besides, the use of computer simulation have been proposed and executed to tackle the issues of manufacturing cost reduction. A simulation model is an instrument in analyzing execution. Even though next studies of the outcomes of simulation can be used for investigation of design of experiment, investigation of optimum manufacturing process parameter to reduce the cost of manufacturing. Therefore, this paper deals with the optimization of process parameters in a manufacturing system to minimize the Unit Manufacturing Cost (UMC) of Un-plasticized Poly Vinyl Chloride pipes using a combined Simulation–Taguchi approach. With the new perspectives of integrated modeling, the study contributes to the body of knowledge, which also opens a new outlook for further studies. Taguchi design of experiment is useful for managing this study and L27 orthogonal array was selected. Thus, a significant factor along with their optimum combination is using Taguchi techniques to arrive at the least manufacturing cost. The results show that these methods can be useful in reducing the number of experimental trials needed to determine the best operating parameters. The results show that key parameters for optimum performance of the system are feed rate in to the hopper and the optimization of the extruder; The predicted unit cost of manufacturing the selected pipe model is 220 Birr and thus costs decreased by 28.8%., because the utilization of the machine increased by 33%, 34.6% for the worker from the actual performance. As part of the general outcome of this study, Taguchi method was helpful for reduction of unit manufacturing cost either at the product development or at process design stage and identifying optimum control parameter combinations