Yacob Astatke

Design and performance evaluation of an energy efficient routing protocol for Wireless Sensor Networks

In recent years, the advancements in wireless communications and electronics have enabled the development of low-cost, low-power and multi-functional Wireless Sensor Networks (WSNs). As nodes in sensor networks are equipped with a limited power source, efficient utilization of power is a very important issue in order to extend the network lifetime. In this paper, a routing protocol namely GAICH (Genetic Algorithm Inspired Clustering Hierarchy) that provide efficient energy management for WSNs is proposed. This protocol makes use of Genetic Algorithm(GA) to create optimum clusters in terms of energy consumption. Using a standard radio energy dissipation model that is used for the simulation of WSNs, the performance of this algorithm is simulated and compared with an already existing LEACH routing protocol for WSNs.

An online revolution in learning and teaching

College-level online learning took off in a big way in 2012, and is likely to impact every department and teacher in some manner. This workshop will highlight major developments in online education technology in engineering and computer science. The workshop will highlight recent online trends like flipped classrooms and MOOCs, will survey various authoring and delivery platforms like EdX and Zyante, summarize some research on online/flipped teaching, discuss methods for instructors to collaborate on delivering instructional experiences, and highlight experiences by teachers of online and hybrid courses.

Improving and Expanding Engineering Education in the Middle East and Africa Using Mobile Learning Technology and Innovative Pedagogy

Recent innovations in inexpensive and portable laboratory instruments have enabled new pedagogical approaches in the teaching of theoretical concepts and design practices in electrical engineering (EE). Faculty members at six universities in the USA have pioneered the use of these new tools to incorporate hands-on experimental activities into existing lecture courses. This has led to restructured EE courses with a focus on student-centered learning and not instructor-centered lectures. The goal of this effort has been to evaluate whether a more student-centered learning environment can stimulate a deeper understanding of EE principles and increase student engagement. The use of hands-on experiments started with an introductory electric circuits course and has expanded into physics, biology, and higher level EE courses. Several modes of instruction using this technology and pedagogy have been implemented at different institutions. In the blended approach, the classroom experience is a combination of lectures and hands-on activities using the mobile laboratory instruments to reinforce theoretical concepts. For the second instructional model, the inverted or flipped classroom, students are expected to read material at home, prior to their investigation of the concepts via hands-on activities in the classroom. A third model uses the portable laboratory instruments to complete hands-on activities outside of the classroom as homework problems, design projects, and/or a nontraditional laboratory component.

Energy efficient Grid Clustering Hierarchy (GCH) routing protocol for wireless sensor networks

The recent developments in high speed computing electronics and wireless communications have created an opportunity for the advancement in power efficient and low cost Wireless Sensor Networks (WSNs) with diverse areas of applications. But wireless sensor nodes are limited in power. To extend the network lifetime of the nodes in the WSN, efficient power utilization is an important variable to be optimized. In this paper, a routing protocol called Grid Clustering Hierarchy (GCH) that provides an efficient energy management for WSNs is proposed. This protocol divides the network into a variable number of virtual grids based on the current average energy of the network to create optimum clusters in terms of energy consumption. Using a standard radio energy dissipation model that is commonly used for simulation of WSNs, GCH is simulated and its performance is compared with a well-known routing protocol for WSNs named LEACH.

Models of adoption and best practices for mobile hands-on learning in electrical engineering

Pedagogical practices in electrical engineering education have been shifting away from teacher-centered learning during the past decade. An innovation that has enabled the adoption of inquiry-based and problem-based learning into the curriculum using experimentation coupled with simulation and analysis has been the development of portable oscilloscopes and other instruments that rely on tablet or laptop computers to perform some of the data processing and to act as the display. Faculty members at six institutions of higher learning have incorporated hands-on experimental activities into existing courses and/or developed new courses that take advantage of these new tools. Assessment data collected by these faculty members have demonstrated that the change towards student-centered learning facilitated by portable electronics increased student interest in electrical engineering, built student confidence in their ability to design circuits and systems, and supported the development of a deeper understanding of the theories that the students investigate or apply in the hands-on activities. A summary of the challenges that are faced in the different implementation models and a discussion of best practices are presented.

Use of K-means clustering for spectrum efficiency in complex networks

In this work the problem of spectrum efficiency in wireless networks over aeronautical channels is studied and a solution by combining direct communications (LOS) and cooperative networking is proposed. In aeronautical communications due to large scale communication paths and sudden changes in the channel topology, extra measures needs to be taken to accommodate reliable and continuous communication for the flying articles. High ground speed of the mobile nodes is also another factor which needs to be accounted for in the network design. The proposed network management technique is dynamic in all senses and ensures connectivity at any given time.

Performance Management in Mixed Wireless Networks Using Multi Distortion Measures

We discuss a new approach that uses a modified k-means clustering algorithm for modeling and managing performance in a cellular and ad-hoc mixed wireless network. This paper describes the analytical foundation and provides extensive simulation results to prove that the enhanced clustering scheme can be used to organize nodes in the mixed network so that its performance is jointly optimized using three different distortion measures: location, traffic, and interference. The paper concludes by showing that the proposed clustering algorithm can be extended by using additional distance measures such that the mixed network is organized and jointly optimized for QoS, spectrum, or interference management.

Managing QoS in mixed wireless networks using the power performance measure

Research conducted at Morgan State University (MSU) has proposed a new approach for modeling and managing Quality of Service (QoS) in a cellular and ad-hoc mixed wireless network. This paper focuses on two key areas. It first introduces the “power” performance measure to model and manage the QoS requirements for wireless nodes with time critical applications as a function of the traffic level. It then presents a modified k-means clustering algorithm to organize nodes in the mixed network. This paper describes the analytical foundation and provides extensive simulation results to prove that the “power” performance measure is an excellent tool for significantly enhancing the QoS performance of the mixed network and maintaining that performance level under severe operating conditions. The paper concludes by showing that the enhanced clustering scheme can be extended by using additional distance measures such that the mixed network is organized and jointly optimized for QoS, spectrum, or interference management.

Energy efficient smart antenna system using Recursive Least Square algorithm and Kaiser side lobe cancellation technique

This work presents an energy efficiency (EE) investigation of a beam generated by the combination of Recursive Least Square (RLS) algorithm and Kaiser side lobe cancellation technique in smart antenna system. The RLS-Kaiser combination is investigated using energy model which is a function of beam width, range and signal to noise plus interference ratio (SNIR). The investigation carried out on linear array geometry with element spacing 0.5 λ. The EE versus range and the EE versus beam width are examined. Finally, we have shown the advantage of using RLS-Kaiser combination during beam formation. And this combination helps for achieving both spectral efficiency (SE) and energy efficiency (EE) at the same time by avoiding interference because of side lobe and by saving the energy that would be wasted as a side lobe respectively. From the result, applying the side lobe attenuation factor in increasing order: 1.3226, 2.1166, 3.3953, and 3.9754 results in decreasing the amount of sidelobe level by 25dB, 30dB, 40dB, and 45dB) respectively with the expense of small increase in beam width. Therefore, even if the main beam width increased due to the saved side lobe energy, on the other hand, the energy efficiency of the generated beam getting improved as the attenuation factor changes from smaller to larger values.

USING EXPERIMENTAL CENTRIC LEARNING PEDAGOGY TO IMPROVE ECE EDUCATION IN THE USA AND AFRICA

This paper will present preliminary results from a 4 year collaboration of 13 electrical and computer engineering (ECE) programs in the USA that are working collaboratively on the development, implementation, and expansion of Experimental Centric based instructional Pedagogy (ECP) in essentially all engineering courses in which electronics plays a significant role. ECP consists of instructional methods that allow students to use portable laboratory instrumentation to learn through hands-on practices, experiential learning, and group work from anywhere at anytime. The authors have also implemented a similar technology and pedagogy at several universities in Africa, including Ethiopia (5 universities), South Africa, and Nigeria. ECP is being implemented in such a large number of educational environments both in the USA and in Ethiopia, that most practical barriers are being identified and addressed. This paper will report on how the partners have created unique versions of pre-tested modules, experiments, units etc. that address a small number of fundamental concepts in circuits and electronics. It will discuss the short and long-term outcomes of this project based on assessment data that has been collected over a three year period. The study concludes on the implications of these influences and the need for further research on how students, faculty, and instructional practices change when using experimental centric learning.