Browsing by Author "Dereje, Shiferaw"

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    Challenges of National Bank Directives on Forex Utilization of Private Commercial Banks
    (Addis Ababa University, 2019-06) Dereje, Shiferaw; Yohannes, Workaferahu (PhD
    The aim of the study was to identify the challenges of Private Banks’ Forex utilization due to NBE Directives. NBE is the responsible organ to supervise financial institutions like Banks. There are 16 Private Commercial Banks operating in Ethiopia. Private Banks have been playing an important role in the Country’s overall development. But some directives issued by NBE have been seen as a challenge for these Banks to foster their progress as they deemed. The study revealed that the directives issued by NBE have a negative impact on Forex utilization of Private Banks and discouraged Banks to achieve their goals in a specified period of time. Though NBE requirements or directives are not the sole reasons, most Bank professionals believe that these directives have an impact on their progress. Regarding the methods of the study, both quantitative and qualitative research methods were applied to identify the real challenges of Private Banks. The study covered six pioneers Private Banks branches found in Addis Ababa as per the date of establishment. A total of 87 IB Managers/Heads and Officers participated in the study. A combination of primary and secondary data had been taken for the study. Some secondary sources like directives and annual reports were used to supplement the study. Semi-structured interview randomly selected participants was carried out. The data analyzed conducted through a mixture of exploratory and descriptive research design. It adapted a survey approach with the use of questionnaires designed to elicit opinions about the real challenges of NBE Directives on Forex utilization of Private Banks from IB Managers/Heads and Officers point of view. To analyze the quantitative data, descriptive statistics was applied. The result of the study showed that some directives issued in connection with FCY have an impact on the overall performance of these Banks. Although some directives have been revised, the impact remains the same as the previous ones. The study identified real factors which challenges the Forex utilization of Private Banks. The findings suggested that some directives should be revised.
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    Modeling and Control of Wastewater Treatment PH Neutralization Process Using Fuzzy Logic Controller: Case Study of Kilinto Brewery Industry, Ethiopia
    (Addis Ababa University, 2020-10) Endale, Nega; Dereje, Shiferaw
    Industrial waste water is the aqueous discard that results from the use of water in an industrial manufacturing process or the cleaning activities that take place along the process. Waste water treatment can involve physical, chemical or biological processes or combinations of these processes depending on the required outflow standards. Specifically, chemical process wastewater treatment involves pH neutralization. Wastewater pH neutralization plays an important part in a wastewater treatment process. It is the most important characteristics of waste water treatment and is used to properly control pH value between pH 6.5 and 7.5 which, provides the optimum environment for microorganism activity. However, it is difficult to control a pH process with adequate performance point due to its nonlinearities, time-varying properties and sensitivity to small disturbances behavior of the wastewater when working near the set point. In this thesis, a fuzzy logic based pH control system has been investigated. The first aspect of the research deals with the development of a mathematical model of a specific Wastewater pH neutralization process. It was intended that this model provide an opportunity for the development, implementation, and evaluation of both the conventional (PID) and an advanced fuzzy logic controller with the feedback control approach. In the second part, the design and simulation of the controller is dealt. The MATLAB simulation results were used to evaluate and compare the performance of both the controllers (PID controller and fuzzy logic controller).The effluent that is discharged from kilinto brewery to the environment had a PH variation of 5.8-9. The fuzzy logic controller reduces the ISE by almost 31.3% in average. However FLC again outperforms PID by reducing maximum overshoot by 55.6%. Finally the FLC reduces the settling time by 14.37% in comparison with PID controller in average. The variation of PH is between 6.67 and 7.16 when taking pH value 7 as the set point. Thus, the fuzzy logic controller is able to provide extremely encouraging control performance in terms of tracking, handling different types of disturbance and robustness compared with a conventional PID controller.