Engineering Commons^™

Towards Multipronged On-Chip Memory And Data Protection From Verification To Design And Test, Senwen Kan, Jennifer Dworak

Computer Science and Engineering Theses and Dissertations

Modern System on Chips (SoCs) generally include embedded memories, and these memories may be vulnerable to malicious attacks such as hardware trojan horses (HTHs), test access port exploitation, and malicious software. This dissertation contributes verification as well as design obfuscation solutions aimed at design level detection of memory HTH circuits as well as obfuscation to prevent HTH triggering for embedded memory during functional operation. For malicious attack vectors stemming from test/debug interfaces, this dissertation presents novel solutions that enhance design verification and securitization of an IJTAG based test access interface. Such solutions can enhance SoC protection by preventing memory test …

Novel Locomotion Methods In Magnetic Actuation And Pipe Inspection, Adam Cox

Mechanical Engineering Research Theses and Dissertations

There is much room for improvement in tube network inspections of jet aircraft. Often, these inspections are incomplete and inconsistent. In this paper, we develop a Modular Robotic Inspection System (MoRIS) for jet aircraft tube networks and a corresponding kinematic model. MoRIS consists of a Base Station for user control and communication, and robotic Vertebrae for accessing and inspecting the network. The presented and tested design of MoRIS can travel up to 9 feet in a tube network. The Vertebrae can navigate in all orientations, including smooth vertical tubes. The design is optimized for nominal 1.5" outside diameter tubes. We …

Development And Application Of A Design Flow For Photonic Integrated Circuits, Ifeanyi Achu

Electrical Engineering Theses and Dissertations

Silicon photonics allows for the fabrication of many optical elements on a single photonic integrated circuit (PIC). By taking advantage of the established foundry technology used in the CMOS and silicon’s high refractive index, high feature density manufacturing can be achieved in mass quantities. In CMOS fabrication, from conception of an electronic circuit to testing, the process of designing an electronic circuit is dictated by a design flow which has been developed over the course of decades. This flow includes circuit level design and simulation, layout of the circuit, layout and verification of the chip, fabrication, packaging, and testing. Given …

An Efficient Integrated Circuit Simulator And Time Domain Adjoint Sensitivity Analysis, Jiahua Li

Electrical Engineering Theses and Dissertations

In this paper, we revisit time-domain adjoint sensitivity with a circuit theoretic approach and an efficient solution is clearly stated in terms of device level. Key is the linearization of the energy storage elements (e.g., capacitance and inductance) and nonlinear memoryless elements (e.g., MOS, BJT DC characteristics) at each time step. Due to the finite precision of computation, numerical errors that accumulate across timesteps can arise in nonlinear elements.

Orbital Angular Momentum Orthogonality-Based Crosstalk Reduction: Theory And Experiment, Unaiza Tariq

Electrical Engineering Theses and Dissertations

Full duplex communication systems allow a single channel to be used for simultaneous two-way communication, increasing spectral efficiency. However, full duplex communication systems suffer from the issue of self-interference between local transmitter and receiver antennas. Analog subtraction and signal processing methods have previously been used to reduce this problem. This dissertation proposes the use of waves carrying orbital angular momentum (OAM) to mitigate the problem of self-interference by offering a means of additional isolation between local antennas.

Orbital angular momentum has been widely studied both in the photonics and radio domain. The theoretically infinite orthogonal states of an OAM signal …

Distribution Network Operation With Solar Photovoltaic And Energy Storage Technology, Mohammad Ramin Feizi

Electrical Engineering Theses and Dissertations

Among distributed energy resources, solar photovoltaic (PV) generation has the largest penetration in the distribution networks. Serving electric vehicles (EV) with renewable resource generation would further reduce the carbon footprint of the energy supply chain for electric vehicles. However, the integration of solar PV and EVs in the unbalanced distribution network introduces several challenges including voltage fluctuations, voltage imbalances, reverse power flow, and protection devices’ malfunctions. The uncertainties associated with solar PV integration and electric vehicles operation require significant effort to develop accurate optimization methodologies in the unbalanced distribution systems operation. In this thesis, in order to cope with the …

Study Of Stochastic Market Clearing Problems In Power Systems With High Renewable Integration, Saumya Sakitha Sashrika Ariyarathne

Operations Research and Engineering Management Theses and Dissertations

Integrating large-scale renewable energy resources into the power grid poses several operational and economic problems due to their inherently stochastic nature. The lack of predictability of renewable outputs deteriorates the power grid’s reliability. The power system operators have recognized this need to account for uncertainty in making operational decisions and forming electricity pricing. In this regard, this dissertation studies three aspects that aid large-scale renewable integration into power systems. 1. We develop a nonparametric change point-based statistical model to generate scenarios that accurately capture the renewable generation stochastic processes; 2. We design new pricing mechanisms derived from alternative stochastic programming …

Golightly : A Gpu Implementation Of The Finite-Difference Time-Domain Method, S. David Lively

Electrical Engineering Theses and Dissertations

Traditionally, optical circuit design is tested and validated using software which implement numerical modeling techniques such as Beam Propagation, Finite Element Analysis and the Finite-Difference Time-Domain (FDTD) method. FDTD simulations require significant computational power. Existing installations may distribute the computational requirements across large clusters of high-powered servers. This approach entails significant expense in terms of hardware, staffing and software support which may be prohibitive for some research facilities and private-sector engineering firms. The application of modern programmable GPUs to problems in scientific visualization and computation has facilitated faster development cycles for a variety of industry segments including large dataset visualization, …

Advances In Power System Operation And Optimization, You Lin

Electrical Engineering Theses and Dissertations

The modern power system has witnessed an increasing penetration of distributed energy resources and modern loads with variable frequency drives. The increasing complexity brings great challenges to modern power system operations. Significant efforts have been made to develop more accurate power system operation and optimization methods. The tradeoff between computation and the model structure makes the problem nontrivial to solve and analyze. Enabled by the wide deployment of PMUs and advanced machine learning algorithms, we improve the conventional power system operation and optimization techniques by improving the accuracy of power system measurements, implementing new power system modeling structures, and performing …

Raman Thermometry Of Graphene Based Thermal Materials, Pengcheng Xu

Electrical Engineering Theses and Dissertations

With the growing demand for high performance computing, we are pushing for higher performance integrated circuits at an ever faster rate. Recent advances in semiconductor production technology sees transistors with a 5 nm process devices being produced for consumer use. This enabled engineers to pack tens of billions of transistors in a package no larger than a fingernail. However, that brings up a problem that we have been long battling against. How can we get rid of the heat produced by these billions of transistors. The current electronic performance is bottle-necked by the ability of the package taking heat away …

Empirical Models Of 3d Air-To-Air Communication Channels, Neil Matson

Electrical Engineering Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) often lack the size, weight, and power to support large antenna arrays or a large number of radio chains. Despite such limitations, emerging applications that require the use of swarms, where UAVs form a pattern and coordinate towards a common goal, must have the capability to transmit in any direction in three-dimensional (3D) space from moment to moment. In this work, we design a measurement study to evaluate the role of antenna polarization diversity on UAV systems communicating in arbitrary 3D space. To do so, we construct flight patterns where one transmitting UAV is hovering at …

Optical Microresonator-Based Flow-Speed Sensor, Elie Ramon Salameh

Mechanical Engineering Research Theses and Dissertations

Optical sensors have become more prominent in atmospheric measurement systems, with LiDAR instruments deployed on a variety of earth-bound, air-borne, and space-based platforms. In recent years, the interest in the human exploration of Mars has created a substantial push towards reliable and compact sensing elements for Mars exploration missions, particularly during a spacecraft’s entry, descent, and landing stages. Real-time sensors able to reliably measure the craft’s speed relative to the surrounding atmosphere during these stages are thus of great interest. In this dissertation, a proof-of-concept for an optical microfabricated sensor, which leverages the whispering-gallery-mode (WGM) and Doppler shift principles, is …

Enhanced Design For Testability Circuitry For Test, Hui Jiang

Electrical Engineering Theses and Dissertations

More stringent defect detection requirements have led to the creation of new fault models, such as the cell-aware fault model, that attempts to model defects that might be missed by traditional test sets. Unfortunately, the resulting test sets can be long, and thus we have previously explored a DFT-based (Design for Testability-based) approach to reduce test time by harnessing scan shift cycles for cell-aware defect detection. This approach uses a MISR (Multiple Input Signature Register) structure to capture data on the functional inputs to selected scan flip-flops during the shifting procedure. The final signature in the MISR can then be …

The Transport Of Acoustic Energy At Two-Dimensional Material Interfaces, Jesus Bolivar

Electrical Engineering Theses and Dissertations

The control of vibrational energy within solids is a fundamental engineering challenge with numerous technological applications. While the control of electrons and photons has revolutionized computation and communication, the control of phonons, the quantized particle of vibrational energy, has been far less successful. Acoustic energy is a form of vibrational energy that involves coherent excitations of phonons to form larger elastic waves. It is this coherence that allows it to be a valuable engineering tool for applications in imaging, frequency/time control, and structural monitoring. Traditional methods of reflecting acoustic energy involve interfacing different phases of matter to reflect via an …

Closed-Loop Brain-Computer Interfaces For Memory Restoration Using Deep Brain Stimulation, David Xiaoliang Wang

Electrical Engineering Theses and Dissertations

The past two decades have witnessed the rapid growth of therapeutic brain-computer interfaces (BCI) targeting a diversity of brain dysfunctions. Among many neurosurgical procedures, deep brain stimulation (DBS) with neuromodulation technique has emerged as a fruitful treatment for neurodegenerative disorders such as epilepsy, Parkinson's disease, post-traumatic amnesia, and Alzheimer's disease, as well as neuropsychiatric disorders such as depression, obsessive-compulsive disorder, and schizophrenia. In parallel to the open-loop neuromodulation strategies for neuromotor disorders, recent investigations have demonstrated the superior performance of closed-loop neuromodulation systems for memory-relevant disorders due to the more sophisticated underlying brain circuitry during cognitive processes. Our efforts are …

Second-Order Enhanced Coupling Strength Grating Out-Couplers For A Monolithic Laser-Electro-Absorption Modulator, Maryam Dezfuli

Electrical Engineering Theses and Dissertations

Conventional grating out-couplers in III-V waveguides typically require lengths of several hundreds of microns to outcouple 50 to 90% of the incident optical power. Enhanced coupling strength (ECS) gratings, which reduce the out-coupler grating length to tens of microns, have a large relative permittivity difference between the materials on either side of the grating boundary along with a high index cover layer. With appropriately chosen permittivity and layer thicknesses, the addition of a cover layer “pulls” the peak of the optical mode towards the grating region, resulting in a significant increase in the grating confinement factor. The resulting ECS out-coupler …

First Order Enhanced Coupling Strength (Ecs) Gratings For Laser-Electro Absorption Modulator (Eam) Transmitters, Freddie Castillo Ii

Electrical Engineering Theses and Dissertations

Conventional first-order DBR gratings in III-V waveguides often require hundreds of microns to achieve near 100% reflected power and provide narrow spectral reflectivity width for a single wavelength, limiting temperature performance of devices. Narrow reflectivity spectral width is desired for spectroscopy and wavelength division multiplexing applications where device temperature is regulated. However, Enhanced Coupling Strength (ECS) gratings provide in-plane reflectors with significantly higher reflected power per unit length, broad spectral reflectivities, and reduced losses at the waveguide-grating interface in III-V waveguides. These properties of ECS gratings allow integration of optical components such as high-speed modulators with short horizontal cavity lasers …