Engineering Commons^™

Design Of A Distributed Real-Time E-Health Cyber Ecosystem With Collective Actions: Diagnosis, Dynamic Queueing, And Decision Making, Yanlin Zhou

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, we develop a framework for E-health Cyber Ecosystems, and look into different involved actors. The three interested parties in the ecosystem including patients, doctors, and healthcare providers are discussed in 3 different phases. In Phase 1, machine-learning based modeling and simulation analysis is performed to remotely predict a patient's risk level of having heart diseases in real time. In Phase 2, an online dynamic queueing model is devised to pair doctors with patients having high risk levels (diagnosed in Phase 1) to confirm the risk, and provide help. In Phase 3, a decision making paradigm is proposed …

Position/Speed Sensorless Control For Permanent-Magnet Synchronous Machines, Yue Zhao

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Permanent-magnet synchronous machines (PMSMs) are widely used in industrial applications owing to their distinctive advantages, such as high efficiency, high power density, and wide constant power region. To achieve high-performance field oriented control, accurate rotor position information, which is usually measured by rotary encoders or resolvers, is indispensable. However, the use of these sensors increases the cost, size, weight, and wiring complexity and reduces the mechanical robustness and the reliability of the overall PMSM drive systems. The goal of the research for this dissertation was to develop a rotor position/speed sensorless control system with performance comparable to the sensor-based control …

Maintenance Optimization For Substations With Aging Equipment, Haifeng Ge

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Today’s electric utilities are confronted with a myriad of challenges that include aging infrastructure, enhanced expectation of reliability, reduced cost, and coping effectively with uncertainties and changing regulation requirements. Utilities rely on Asset Management programs to manage inspections and maintenance activities in order to control equipment conditions. However, development of strategies to make sound decisions in order to effectively improve equipment and system reliability while meeting constraints such as a maintenance budget is a challenge.

The primary objective of this dissertation is to develop models and algorithms to study the impact of maintenance toward equipment/system reliability and economic cost, and …

Design And Development Of A Low-Cost High Range Resolution X-Band Radar, Paul C. Cantu

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Synthetic Aperture Radar (SAR) is one of the main tools for microwave remote sensing because of its multi-dimensional high resolution characteristics and the capability to operate in nearly all weather conditions, day and night. The University of Nebraska-Lincoln (UNL) initiated the design and development of a low-cost airborne SAR in January 2001 to support our Airborne Remote Sensing Program. The objectives of this project are separated into various evolutionary stages. This thesis will focus on the initial phase of design and construction of an X-band high range resolution radar (HRR) using basic RF /microwave and digital components. The following stages …