The ability of a machine to synthesize textual output in a form of human language is a long-standing goal in a field of artificial intelligence and has wide-range of applications such as spell correction, speech recognition, machine translation, abstractive summarization, etc. The statistical approach to enable such ability mainly involves...
This thesis reports on the use of optical antennas, and more broadly, metal optics for the engineered collection and enhancement of infrared photodetectors. These ideas would be useful in enhancing at other wavelengths and other types of detectors, but this work is specifically focused on the Quantum Well Infrared Photodetector...
As Power and Energy become the limiting factors for computer designs and systems, a holistic approach for tackling inefficiencies needs to be adopted. Computations need to be classified based on their importance and impact on the end quality, power consumption, and runtime so that the system can perform the needed...
A practical challenge in wireless communication systems is acquisition of channel state information at the transmitter and the receiver. In this thesis, we address the problem of training and limited-rate feedback optimization for fading channels. In a wideband (multi-carrier) channel, given limited coherence time and power, only a finite number...
Several challenges exist in cardiac magnetic resonance imaging (MRI) as a result of the constant motion of the heart. In order to create a cardiac image with both high spatial and temporal resolution, MR data must be obtained from multiple cardiac cycles; therefore, a means of synchronization for segmented acquisition...
The III-Nitride material system has already proven to be commercially viable for blue light emitting diodes (LEDs), blue laser diodes (LDs), and near UV photodetectors. Continued interest in this field has driven the desire for even lower emission and detection cut-off wavelengths into the solar-blind / deep UV portion of...
This thesis focuses on resource allocation in wireless communication and networking. Resource allocation has been studied widely, for example, to maximize the system-wide throughput or to minimize the average delay per user. Moreover, the utility-based framework is becoming an important tool for addressing fairness and Quality-of-Service (QoS) for individual users....
All-optical switches have far reaching applications in both quantum and classical information processing. Most current all-optical switches depend on intense interactions between light and nonlinear media which may be extremely inefficient. The need for high switching beam powers have prevented all-optical switching from being very useful in most applications. Our...
As device sizes decrease, more functionality can be placed in an integrated circuit. Therefore, the design complexity of these circuits increases. To deal with complexity, designers move to higher abstraction levels. Currently, the highest abstraction level is the system-level. In our work we investigate the synthesis and verification problem at...
The semiconductor-based Quantum Cascade Laser (QCL) offers several key advantages over gas lasers, solid-state lasers, and other semiconductor-based mid-infrared lasers. While the QCL has historically operated best in the λ ~ 7-9 μm range using InP-based materials, a major challenge has been to achieve a high-power, room-temperature continuous-wave (CW) operation...
Atrial fibrillation (AF) is the most common supraventricular tachyarrhythmia and its prevalence is expected to increase with the aging population. However, the mechanisms AF initiation, maintenance and termination are not completely understood. The surface electrocardiogram (ECG) characteristics are a direct reflection of pathophysiologic events in the atria and can be...
As we move into deeper sub-micron technologies, the complexity of pushing the circuit performance further is becoming an important obstacle. To achieve better performance, there is an increasing need for collaboration of higher level (e.g. microarchitecture-level) and circuit level optimizations. Traditionally for a computer system, applications lie at the top...
Process scaling has enabled the production of integrated circuits with millions of transistors. System-on-a-Chip becomes feasible as more functionalities can be packed into a single chip. As the human brain power is limited, the design process of such sophisticated systems should be automated in order to meet the stringent design...
The growing technological industry is demanding the development of powerful and smaller devices. Dielectric thin-films can play an important role to help push towards achieving these goals. However, their advantage of high-quality material and low material costs compared to bulk can only be achieved with consideration of the technique, conditions,...
Visual object tracking, i.e. consistently inferring the motion of a desired target from image sequences, is a must-have component to bridge low-level image processing techniques and high-level video content analysis. This has been an active and fruitful research topic in the computer vision community for decades due to both its...
Integrated circuits have been continuously scaled to increase speed and integration density as a means to improve the performance or pack more functionality. However, an extremely enormous amount of effort is needed to further scale the dimensions in deep submicron technologies. As technology scaling is slowing down and design complexity...
Integrated circuits have been continuously scaled to increase speed and integration density as a means to improve the performance or pack more functionality. However, an extremely enormous amount of effort is needed to further scale the dimensions in deep submicron technologies. As technology scaling is slowing down and design complexity...
As manufacturing technology moves toward fundamental limits of silicon CMOS processing, it is increasingly important to utilize the full potential of available transistors and interconnects. While manufacturing technology faces fundamental limits inherent in physical laws or material properties, design and verification technology faces fundamental limitations inherent in the computational intractability...
Leakage currents limit the operation of high performance type II InAs/GaSb superlattice photodiode technology. Surface leakage current becomes a dominant, limiting factor to the ideal performance of a photodiode, especially at the scale of a focal plane array pixel (< 25 µm), and must be addressed. A reduction of the...
Multi-hop wireless networks hold promise for increasing network capacity, lowering power requirements, and improving coverage over traditional cellular networks. However, their widespread adoption is hampered by challenges that include: 1) unreliable and complex routing protocols due to the transient nature of wireless nodes, 2) difficulties in guaranteeing quality of service...