Browsing by Author "Dereje Nigussie"

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    Influence of Leadership Styles on Team Performance in Ethiopian Biomedical and Public Health Institutes
    (Addis Ababa University, 2025-08) Dereje Nigussie; Tekelgorgis Assefa
    The research topic is to look at how different leadership styles affect the performance of teams within Ethiopian Biomedical and Public Health Institutes. It seeks to understand how transformational, transactional and servant leadership shapes the relationships among team members, their communication and decisions about talent. For data collection a mixed-methods approach has been used to process giving surveys to 198 people and interviewing others to access both types of data. The study shows that using transformational leadership can greatly improve how well a team performs by supporting motivation, trust and teamwork. Moreover, having the right organizational culture and effective ways to communicate influences a lot in determining team success. From these outcomes, we understand the value of training leaders to be flexible and supportive in the workplace which is important for achieving better public health outcomes
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    Modeling the Impact of Traffic Factors on Queue Length at Consecutive Signalized Intersections
    (Addis Ababa University, 2025-02) Dereje Nigussie; Yonas Minalu (PhD)
    Urbanization and increased vehicular traffic have led to significant challenges in managing traffic flow at signalized intersections, particularly in developing countries. This study focuses on optimizing traffic flow at consecutive signalized intersections by analyzing the factors affecting queue dynamics. The objectives include modeling the impacts of pedestrian volume, signal green time allocation and proportion of buses presence on queue length. Using a simulation-based approach with SUMO software, the study modeled various traffic scenarios to understand the interactions between vehicles, pedestrians and signal timing. Key findings highlight that queue lengths are heavily influenced by signal timing inefficiencies, pedestrian crossing during vehicle gaps and the presence of proportion of buses, which exacerbate delays and reduce intersection capacity. A multinomial linear regression model was developed to assess the impact of pedestrian volume, proportion of buses and green time on the performance of two consecutive signalized intersections. The regression model yielded significant results, with an adjusted R square value close to one, indicating a strong correlation between pedestrian volume, proportion of buses and green time and probability of queue formation. Factors such as pedestrian volume, proportion of buses and green time were found to be statistically significant in influencing the performance. This research contributes to the field of urban traffic management by providing insights into optimizing signal timing strategies and addressing the unique challenges of mixed traffic conditions.