Engineering Commons^™

Modeling, Simulation And Control Of Microrobots For The Microfactory., Zhong Yang

Electronic Theses and Dissertations

Future assembly technologies will involve higher levels of automation in order to satisfy increased microscale or nanoscale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to the microelectronics and MEMS industries, but less so in nanotechnology. With the boom of nanotechnology since the 1990s, newly designed products with new materials, coatings, and nanoparticles are gradually entering everyone’s lives, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than top-down robotic assembly. This is due to considerations of volume handling of large …

Modeling And Simulation Methodologies For Spinal Cord Stimulation., Saliya Kumara Kirigeeganage

Electronic Theses and Dissertations

The use of neural prostheses to improve health of paraplegics has been a prime interest of neuroscientists over the last few decades. Scientists have performed experiments with spinal cord stimulation (SCS) to enable voluntary motor function of paralyzed patients. However, the experimentation on the human spinal cord is not a trivial task. Therefore, modeling and simulation techniques play a significant role in understanding the underlying concepts and mechanics of the spinal cord stimulation. In this work, simulation and modeling techniques related to spinal cord stimulation were investigated. The initial work was intended to visualize the electric field distribution patterns in …

Thermal And Structural Modeling Of Electrochromics On Glass, Mahesh B. Manandhar

Electronic Theses and Dissertations

Advanced glazing is a type of window glazing that interacts with the surrounding environment to change its thermal and optical properties to create a more comfortable and energy efficient indoor environment. Electrochromics are one type of such advanced glazing materials that change their properties in response to an externally applied voltage controllable by the user or by automation.

The effectiveness of electrochromics depends upon how well it can keep off extreme temperature conditions from outdoors all year round as well as how structurally stable it can remain at such conditions. This research investigates the use of COMSOL, a finite element …

Modeling And Simulation Of All-Electric Aircraft Power Generation And Actuation, David Woodburn

Electronic Theses and Dissertations

Modern aircraft, military and commercial, rely extensively on hydraulic systems. However, there is great interest in the avionics community to replace hydraulic systems with electric systems. There are physical challenges to replacing hydraulic actuators with electromechanical actuators (EMAs), especially for flight control surface actuation. These include dynamic heat generation and power management. Simulation is seen as a powerful tool in making the transition to all-electric aircraft by predicting the dynamic heat generated and the power flow in the EMA. Chapter 2 of this dissertation describes the nonlinear, lumped-element, integrated modeling of a permanent magnet (PM) motor used in an EMA. …

Unified Large And Small Signal State-Space Based Modeling And Symbolic Simulation For Pwm Converters, Ehab Shoubaki

Electronic Theses and Dissertations

In this Dissertation, which concentrates on discrete modeling for control purposes of DC/DC converters and simulation through symbolic techniques. A Unified Discrete State-Space Model for power converters in CCM is presented. Two main approaches to arriving at the discrete model are used. The first approach involves an impulse function approximation of the duty cycle modulation of the converter switches, and this approach results in a small signal discrete model. The Second approach is direct and does not involve any approximation of the modulation, this approach yields both a large signal nonlinear discrete model and a linear small signal model. Harmonic …

Signal Processing Of An Ecg Signal In The Presence Of A Strong Static Magnetic Field, Aditya Gupta

Electronic Theses and Dissertations

This dissertation addresses the problem of elevation of the T wave of an electrocardiogram (ECG) signal in the magnetic resonance imaging (MRI). In the MRI, due to the strong static magnetic field the interaction of the blood flow with this strong magnetic field induces a voltage in the body. This voltage appears as a superimposition at the locus of the T wave of the ECG signal. This looses important information required by the doctors to interpret the ST segment of the ECG and detect diseases such as myocardial infarction. This dissertation aims at finding a solution to the problem of …

Modeling And Simulation Of Long Term Degradation And Lifetime Of Deep-Submicron Mos Device And Circuit, Zhi Cui

Electronic Theses and Dissertations

Long-term hot-carrier induced degradation of MOS devices has become more severe as the device size continues to scale down to submicron range. In our work, a simple yet effective method has been developed to provide the degradation laws with a better predictability. The method can be easily augmented into any of the existing degradation laws without requiring additional algorithm. With more accurate extrapolation method, we present a direct and accurate approach to modeling empirically the 0.18-ìm MOS reliability, which can predict the MOS lifetime as a function of drain voltage and channel length. With the further study on physical mechanism …

Evolving Models From Observed Human Performance, Hans Karl Gustav Fernlund

Electronic Theses and Dissertations

To create a realistic environment, many simulations require simulated agents with human behavior patterns. Manually creating such agents with realistic behavior is often a tedious and time-consuming task. This dissertation describes a new approach that automatically builds human behavior models for simulated agents by observing human performance. The research described in this dissertation synergistically combines Context-Based Reasoning, a paradigm especially developed to model tactical human performance within simulated agents, with Genetic Programming, a machine learning algorithm to construct the behavior knowledge in accordance to the paradigm. This synergistic combination of well-documented AI methodologies has resulted in a new algorithm that …

Autonomous Environmental Mapping In Multi-Agent Uav Systems, Linus Jan Luotsinen

Electronic Theses and Dissertations

UAV units are by many researchers and aviation specialists considered the future and cutting edge of modern flight technology. This thesis discusses methods for efficient autonomous environmental mapping in a multi-agent domain. An algorithm that emphasizes on team work by sharing the agents local map information and exploration intentions is presented as a solution to the mapping problem. General theories on how to model and implement rational autonomous behaviour for UAV agents are presented. Three different human and tactical behaviour modeling techniques are evaluated. The author found the CxBR paradigm to be the most interesting approach. Also, in order to …