Mustefa Jibril

In this paper, an electromechanical mass lifter system is designed, analyzed and compare using optimal and robust control theories. LQR and μ -synthesis controllers are used to improve the lift displacement by comparison method for tracking the desired step and sinusoidal wave signals input. Finally, the comparison simulation result prove the effectiveness of the electromechanical mass lifter system with μ -synthesis controller for improving the rise time, percentage overshoot, settling time and peak value of tracking the desired step displacement signal and improving the peak value for tracking the desired sinusoidal displacement signal with a good performance.

In this paper, the design and analysis of coupled tank water level control system is done using robust control theory. The main aim of this work is to improve level controlling mechanisms in industries and household areas. In this paper, H ∞ and μ –synthesis controllers are designed to improve the level control system. The coupled tank water level control system is designed using the proposed controller’s comparison and tested for tracking a reference level signals (step, sine wave and random) and simulation results have been analyzed successfully. Finally the comparative simulation results prove the effectiveness of the proposed coupled tank water level control system with H ∞ controller for improving the tracking mechanism performance of the system.

This study was carried out to determine the prevalence of, and reasons for the various forms of addictive use among the students of the University of Dire Dawa. The research system is used, cross-sectional, questionnairequestion. This study has been carried out, including the first-and second-year students at the University of Dire Dawa. The study included 164 students who have completed a structured questionnaire. The Data was analyzed on SPSS version 16. The prevalence of addictive use was 20.7%, with 64.7% of the male students are dominating. It is the most common addiction among students was that the Chewing of Chat (38.2%), followed by cigarette smoking (23.5%), marijuana smoking (17.6%), shisha smoking (8.8%), alcohol (6%), and 5.9% were of other addiction. The most important factor appears to be the pleasure to compete and not being able to love. The vast majority of addictive users of the students (47.1%) were motivated by the friends of the start of an addiction. addictive usage among university students, even though they are well known about their dangers, a cause for concern. Education, training, counseling, and proper training can help prevent the dependency of prospective students, who are expected to serve the community.

This study aimed to compare the levels of self-esteem among Dire Dawa University Male Technology students for the program of computer science (CS), Information Technology (IT), Computer Engineering (CE). Subjects for this study were randomly selected. 90 students (30 in Computer Science, 30 in Information Technology, and a 30-in Computer Engineering) were selected as the subjects for this study. The self-esteem of the assessment, so that the student has been Prepared by Rekha Agnihotri self-confidence Inventory (ASCI). For the comparison between groups at a value of 0.05, for a one-factor, an ANOVA test was performed. The results show that when a difference was found between the different disciplines of the male students had a higher level of self-esteem (p) Based on the results obtained, the conclusion was that the mean self-esteem scores of the students in Information Technology (27.57) are higher than that of the students in the Computer Science and Computer Engineering.

This research was conducted at 15 government schools in Addis Ababa. The objectives of this research are to identify principal style and its effect on academic achievement. The “Leader Behavior Description Questionnaire” (LBDQ) formed by Halpin (1966) was used. Meanwhile Academic achievement was measured using the “School Certificate Examination Results from 2017-2020. A total of 191 teachers and 15 principals from government school in Addis Ababa were randomly chosen. Pearson correlation was used to analyze the data. To support data obtained from questionnaire given 10 teachers were interviewed. The results showed that most of the school leaders adopt a democratic style of leadership. There was a significant correlation between the structure of task-oriented leadership style and students’ performance in the examinations. Correlation analysis also showed that principals practice task- oriented structure and consideration-oriented structure in relation to their work responsibilities. Furthermore, findings also showed that majority of the principals are more likely to practice consideration-oriented leadership style compared to structure-oriented leadership style.

The study, designed to find out the gender outcome, gender roles, and labeling of labels in the department's head examination, was conducted using 194 study participants recruited from lecturers at Dire Dawa University in Ethiopia 116 women and 78 were males aged 29.23. The following five labels are used: Department head in general, efficient male Department head, efficient female Department head, inefficient male Department head, and inefficient female Department head) were responded to by the research participants. Seven different hypotheses were tested using ANOVA. Findings revealed that gender role orientation had a significant effect on the evaluation of the Department head. Furthermore, there were no significant effects of gender, and attachment of labels on the evaluation of Department head and no interaction effects of gender and gender role orientation, gender and attachment of labels and gender, gender role orientation, and attachment of labels on the evaluation of Department head.

The present study was conducted to compare the attitude of Dire Dawa University Lecturers Attitude Towards using Slide Projectors. The sample for the proposed study consisted of 120 lecturers (social science: Male=30, Female=30)(Natural science: Male=30, Female=30). A random sampling strategy was followed to draw the sample for the study. The data were subjected to various statistical treatments. The results reveal the male dire Dawa University and Natural science lecturers have a favorable attitude towards using Slide Projectors.

The main objective of the suspension of a vehicle is to maximize the contact between the vehicle tires and the road surface, provide steering stability and provide safe vehicle control in all conditions, evenly support the weight of the vehicle, transfer the loads to springs, and guaranteeing the comfort of the driver by absorbing and dampening shock. This paper discusses the kinematic design of a double a-arm Suspension system for ABAY Vehicle. The hardpoint's location can be determined using this procedure to simulate motion in any kinematic simulation software. Here, Optimum Kinematics is used as kinematic simulation software. The method illustrated deals with the basics of Kinematics which helps to predict the characteristics of the suspension even before simulating it in the kinematic simulation software.

The purpose of the existing examination has changed to gain access to the "Ethiopian Higher Education Students' Status of Physical Education". The current study was conducted on 800 students (500 males and 300 females) between the ages of 20 and 26 years. The subjects were Ethiopian Higher Education Students, Addis Ababa, and Dire Dawa. Topics were Ethiopian Higher Education Students, Addis Ababa, and Dire Dawa. The responses collected from the given studies were converted into raw data with the help of a frequency distribution method. The data were then sorted as a result of a percentage study method.

Chewing Khat is one of the leading causes of mental disorders in Ethiopia. An alarming increase in Khat chewing among adults since the early 1990s was reported. Studies have shown that starting chewing Khat early in life is associated with an increased risk of adverse health effects. The objective of the study: This study was conducted to measure the increase in Khat chewing among students at Dire Dawa University students in Dire Dawa City, identify the natural causes of the problem, and demonstrate students' knowledge of the effects of Khat chewing. Material and Methods: The study was separate. Dated February 2021. Students during study time (n = 302) were included. The information was collected through personal interviews and completed a list of questions prepared after reviewing. RESULTS: Male (88.2%) of responding students chewed Khat with a significant difference (P <0.001) between males and females in terms of chewing. The year of student study, academic achievement, and family history of chewing Khat had a significant impact (P <0.05) on chewer students. Of the Khat chewer students who read 35.6% reported chewing both morning and afternoon. 66.7% of students who chewed reported that they had intentions to stop chewing and 82.4% considered chewing to be dangerous. CONCLUSION: Khat chewing gum among students is considered a problem and efforts are needed to help students stop chewing and this is considered a way to prevent Khat chewing among students.

In this paper an attempt has been made towards the design and evaluation of a solar parabolic trough collector (PTC) system integrated with a conventional oil boiler (COB) to increase the energy utilization effectiveness and reduce the environmental emission of the existing conventional oil boiler in the Kombolcha textile factory, in Ethiopia. The factory uses 8500 ton/annum of heavy fuel oil to generate 26 ton/hour of pressurized hot water at 140C temperature which causes an increase in greenhouse gas emissions, so the solar parabolic trough collector hot water generation system will be an appropriate solution for this application. Based on the available annual solar radiation, estimates of the solar fraction, solar energy unit price and system pay-back period have been carried out. The proposed system has the potential to save 1055.9 ton/year of fuel oil. The unit cost of PTC solar energy is estimated to be 0.0088 $/kWh and the payback period of the plant is five years. Since the unit price of oil energy (0.0424 $/kWh) is much greater than the unit price of solar energy by a substantial margin (0.033 $/kWh) in Ethiopia, therefore the water heating system by a solar parabolic trough collector is a feasible alternative to heating by a conventional oil boiler.

Proportional integral observer (PIO) for tracking a nonlinear method has a lower sentiency to cipher the state and output variables. So a more nonlinear controller has to be else to control to activity. In this paper, a fuzzy logic (FLC) controller has been added to the PIO to meliorate the calculation transmute. A fuzzy proportional integral observer (FPIO) for following a nonlinear system has been premeditated to decimate the susceptibleness to cipher the tell and turnout variables with the existent posit and product variables. The FPIO controller has been tested for improving the estimation control using a nonlinear quarter vehicle active suspension system with a nonlinear hydraulic actuator. A comparison simulation of the proposed nonlinear system for estimating the state variables and tracking the output (suspension deflection) with a set point bump road disturbance using FPIO and PIO. The comparison simulation result shows that the estimated state variables and system output match the actual ones perfectly using a fuzzy PIO controller.

A ventilator is a device that provides cool air by moving the air in or out of the lungs, inhaling a patient who is not fit to smell, or breathing properly. In this paper, a resistive chest belt sensorbased mechanical ventilator is designed to provide the COVID-19 patient with the volume of air you need to deliver with the expansion of the patient's chest in need of more air. The resistive band sensor senses the expansion of the patient's chest and controls the solenoid valve attached to the oxygen compressor. The function of the respirator is tested with the MATLAB / Simulink tool with the help of a Proportional Integral Derivative (PID) Controller and a promising result obtained.

Accurate and precise trajectory tracking is crucial for a quadrotor to operate in disturbed environments. This paper presents a novel tracking hybrid controller for a quadrotor UAV that combines the Adaptive and Fuzzy logic controller. The Adaptive fuzzy controller is implemented to govern the behavior of two degrees of freedom quadrotor UAV. The proposed controller allows controlling the movement of UAVs to track a given trajectory in a 2D vertical plane. The Fuzzy Logic system provides an automatic adjustment of the Adaptive parameters to reduce tracking errors and improve the quality of the controller. The results showed perfect behavior for the control law to control a quadrotor trajectory tracking task. To show the effectiveness of the intelligent controller, simulation results are given to confirm the advantages of the proposed control method, compared with Fuzzy and Proportional integral derivative (PID) control methods.

The current study was conducted to assess the attitude of higher education students. The current study sample consists of 600 students selected from the Dire Dawa University. The Student Attitude Inventory (SAI) was developed using 6 subsidies given to sample subjects for data collection purposes. The researcher used the most widely accepted and widely used mathematical methods to analyze and interpret data including mean, SD and t‐test. The results showed that male students had a better and more positive attitude towards the learning process and its affiliates. In addition, these results also showed that urban students had a better learning environment than in rural areas.

This study aimed to examine the perception of Engineering students about importance of educational needs and satisfaction about it. A descriptive correlational design was used for this study. The present study was conducted at engineering faculties in Dire Dawa University. The present study included a total coverage sample includes all four academic years engineering students during academic year (2021). Total number of students was (n = 727). The study tool consisted of Engineering Education Satisfaction Instrument (EESI) consist of two questions (question one about importance of educational needs and question 2 about satisfaction with the educational needs) contained the same items, the five sub‐scales related to the five levels. This study revealed that, there was a highly statistical significant differences among the four academic years engineering students as all 5th year engineering students had reported that the educational needs is very important and a highly statistical significant differences among the students of the 4 academic years in which the second year and 3rd year students had the highest mean scores according to perception of the engineering students about satisfaction with the educational needs. There was a highly statistically significant positive relationship between perceptions of the engineering students in the four academic years about the importance of educational needs. Also, observed that there was a highly statistically significant negative relationship between perceptions of the engineering students in the four academic years about the satisfaction of educational needs. Ask authoritative persons to improve educational environment through providing more space and educational resources for conducting teaching learning process.

The present study was carried out to study the emotional intelligence of Electrical Engineering students in Dire Dawa University Ethiopia. The sample for the study was 90 (30 Industrial control engineering streams, 30 Power system engineering streams, and 30 Communication engineering streams) randomly selected from Dire Dawa university, school of electrical and computer engineering. A sample scale was employed for the data collection and a t-test was employed for the analysis of data. The outcome of the study shows that Industrial control engineering and Power system engineering students do not differ significantly on various dimensions of Emotional intelligence and Industrial control engineering and Communication engineering students do not differ significantly on various dimensions of Emotional intelligence and Power system engineering and Communication engineering students differ significantly on various dimensions of Emotional intelligence.

This paper reflects the students' attitude toward learning English in secondary schools. The current study was conducted following 57 students at Dire Dawa secondary Schools. The findings suggest that students were generally uncomfortable with the language and subject areas offered in secondary school and agreed that learning English is important for them. Respondents to the current study, who had recently received their primary education, reported that the secondary school syllabus helped them to acquire the language needed for work and personal development. The findings of this study also showed a positive attitude towards English learning at Dire Dawa secondary Schools.

In the present study an attempt is made to assess the comparison of adjustment and academic achievement among students in Dire Dawa university, Ethiopia. A total of 100 students studying in Dire Dawa university were randomly selected. They were administered in Students Adjustment Inventory (SAI) which measured adjustment of an individual in 4 areas (Campus Life, health, time management and social life). Academic achievement scores were collected from the respective university. One-way ANOVA was employed to find out the significance of difference between students with different levels of adjustment in various areas and their academic achievement scores. Results revealed that only campus life adjustment had significant influence over academic achievement. Social life, time management and health adjustments did not have significant influence over academic achievement of the sample studied.

This study aimed to examine the influence it is to study skills and academic‐related stress in the academic performance of the students of the university. A descriptive research project was used. The study was carried out among students of engineering at the University of Dire Dawa. The study involved 400 students of the engineering bachelor's degrees, one hundred and from the second to the 5th year which has been evaluated for the academic stress and to study skills. A random sample is used to select objects for the study of the system. Three tools were used: Tool I: Socio‐demographic Profile Sheet, Tool II: Study Skills Assessment Questionnaire, Tool III: Perceived Stress Scale. The results of this study showed that the students performed well in all the subjects, except for the time‐management method and writing skills. More than two‐thirds of the surveyed students have a low level of stress. Academic stress is higher in senior and female students. There was a negative correlation between the student’s stress and their study skills. Statistically significant relationships were found between academic performance, study skills and the stress level of the students surveyed.

The aim of this study is the evaluation of the Success of Graduating with Distinction in Higher Education (SGDHE) using the fuzzy DEMATEL method. The observation has been done using cause and effect criteria. The 11 cause and 14 effect clusters have been used in this study. The study result of this work shows that all the effects are connected to the given causes and a cause‐effect graph has been generated for each connection. This proposed approach is demonstrated with the empirical case of Dire Dawa University students in Dire Dawa Ethiopia.

This study investigates the outlet temperature control for the design of steam condenser. The comparison has been made for a step drop in the steam condenser temperature set point using MATLAB/ Simulink environment for the steam condenser with NARMA-L2 using Levenberg-Marquardt algorithm and NARMA-L2 using resilient backpropagation algorithm controllers. The steam condenser with NARMA-L2 using Levenberg-Marquardt algorithm controller presented excellent and superior dynamic performance in response to the temperature drop in settling time. The overall simulation results demonstrated that the steam condenser with NARMA-L2 using Levenberg-Marquardt Algorithm controller can be an efficient alternative to the steam condenser with NARMA-L2 using resilient backpropagation algorithm controller.

In this study, the performance of inverted pendulum has been Investigated using neural network control theory. The proposed controllers used in this study are NARMA-L2 with Resilient backpropagation and Levenberg Marquardt backpropagation algorithm controllers. The mathematical model of Inverted Pendulum on a Cart driving mechanism have been done successfully. Comparison of an inverted pendulum with NARMA-L2 with Resilient backpropagation and Levenberg Marquardt backpropagation algorithm controllers for a control target deviation of an angle from vertical of the inverted pendulum using two input signals (step and random). The simulation result shows that the inverted pendulum with NARMA-L2 with resilient backpropagation controller to have a small rise time, settling time and percentage overshoot in the step response and having a good response in the random response too. Finally, the inverted pendulum with with NARMA-L2 with resilient backpropagation controller shows the best performance in the overall simulation result.

In this study, a 2 DOF industrial robotic arm is designed and simulated for elbow and wrist angle and velocity performance improvement using robust control method. Mixed H2/H infinity synthesis with regional pole placement and H2 optimal controllers are used to improve the system output. The open loop response of the robot arm shows that the elbow and wrist angles and velocities need some improvement. Comparison of the proposed controllers for an impulse and step input signals have been done and a promising results have been obtained.

Shell tube surface condenser (STSC) is a heat exchanger system that exchange a high pressure steam into low pressure water and it is widely used in applications like textile industries and nuclear power plants. The modelling of the system has been established based on lumped parameters. In this paper, a fuzzy expert system is developed in order to improve the performance of the condenser. A pressure feedback system has been developed to analyze the effect of the condenser output temperature, circulating water flow and heat developed. An experiment has been made for the closed loop system using fuzzy tuned PI, fuzzy logic and PID controllers and a promising results have been obtained successfully.

In this study, the design and control of a hydraulic system based tire changer machine have been analyzed and simulated using MATLAB/Simulink Toolbox successfully. The machine have a displacement input which is a leg pedal displacement in order to push the piston of the pump to fed the motor with a pressured hydraulic fluid to rotate the tire with an angular speed to mount and dismount it. Augmentation based H4 and H2 optimal synthesis controllers have been used to improve the performance of the machine. Comparison of the proposed controllers for tracking a reference input speed have been done using two reference inputs (step and random) signals. Finally, the comparative simulation results proved the effectiveness of the proposed tire changer with synthesis controller in improving the settling time and percentage overshoot.

In this paper, a vertically moving base inverted pendulum control analysis has been done using Matlab/Simulink Toolbox. Because the vertically moving base inverted pendulum system is nonlinear and highly unstable, a feedback control system is used to make the system controlled and stable. A PI and PID controllers are used to improve the stability of the pendulum. Comparison of the vertically moving base inverted pendulum using PI and PID controllers for tracking a desired angular position of the system using a step and random input signals and a promising results have been obtained succesfully