Seed dormancy is defined as the inability of viable seeds to germinate under conditionsotherwise favorable for germination. Dormancy provides a strategy for seeds to germinateat an appropriate time. Abscisic acid (ABA) is a major hormone involved in the regulationof seed dormancy. To elucidate the molecular mechanisms of dormancy, the twoexperimental...
Translation surfaces can be viewed as polygons with parallel and equal sides identified. An affine homeomorphism φ from a translation surface to itself is called pseudo-Anosov when its derivative is a constant matrix in SL₂(R) whose trace is larger than 2 in absolute value. In this setting, the eigendirections of...
Researchers rely on bioeconomic models to guide research and generate fishery management advice for commercial fisheries. Due partly to a paradigm shift towards ecosystem based fishery management, increasing complexity in the characteristics of the problems has meant that bioeconomic simulation models are becoming more prevalent in the fisheries literature. However...
Hybrid automatic repeat request (HARQ) schemes combine packet retransmission with forward error correction to ensure a reliable communications. In multiple-input multiple output (MIMO) systems, interference cancellation (IC) detection is widely used where the detection and cancellation steps of the simultaneously transmitted data streams occur. In principle, the signal stream estimated...
Time-dependent electronic transport is increasingly important to the state-of-the-art device design and fabrication. The development of nanoscale sensing, the harnessing and control of structural fluctuations, and the advancement of next-generation materials all require a treatment of quantum dynamics beyond the level of traditional methods and a more nuanced approach to...
Threshold-based time of arrival (TOA) estimation is a technique for high-precision indoor localization. Existing threshold selection methods, such as xed thresh- old and normalized threshold methods, do not consider the signal-to-noise radio (SNR) value at the receiver. This is not desired for high-precision positioning. A proper threshold value depends on...
Optical wireless communication (OWC) is an alternative to radio frequency (RF)communication with a signi cantly larger and unregulated spectrum. In OWC systems, optical orthogonal frequency division multiplexing (O-OFDM) with intensity modulation and direct detection (IM/DD) is commonly used. There are two common signal structures in most OWC systems based on...
Advances in low-power digital integration and microelectro-mechanical systems (MEMS) have paved the way for micro-sensors. These sensors are equipped with data processing capabilities along with sensory circuits. Sensor data are processed on these individual sensors and transmitted to the target (sink). Lowcost integration and small sizes of these sensors have...
The development and some applications of holographic optical tweezers (HOT) are presented. Our HOT system uses a spatial light modulator (SLM) to control the location and properties of the optical trap. We have developed a method for optimizing the diffraction efficiency of a SLM that can be applied in situ...
IO transactions within a computer system have evolved along with other system components (i.e., CPU, memory, video) from programmed IO (PIO). In current mainstream systems (spanning from HPC to mobile) the IO transactions are CPU-centric descriptor-based DMA transactions. The key benefit is that slower IO devices can DMA write system...
Data converters are essential interface circuits between the analog world that people live in and the digital processors that people live with. Linearity, which often is a tradeoff against other performance criteria, is one of the major performance demands from applications for both analog-to-digital converts (ADC) and digital-to-analog converters (DAC)....
Many algorithms in parallel systems can be easily solved if we can generate a Hamiltonian cycle on the underly network. Finding Hamiltonian cycle is a well known NP-complete problem. For specific instances of regular graphs, such as Torus and Gaussian network, one can easily find Hamiltonian cycles. In this thesis,...
Indoor positioning systems can be used for many applications such as indoor navigation,emergence response, asset monitoring, and shopper assistance. Due to the weak received signal and multipath reflection, the global positioning system (GPS) generally does not work in indoor environments. There are a variety of radio frequency (RF) signals and...
In this paper, we propose a credit-based resource allocation technique for dynamic spectrum access (DSA) systems that is robust against malicious and selfi sh behaviors and ensures good overall system fairness performance while also allowing spectrum users to achieve high amounts of service. We also propose a new objective function...
In modern digital communication systems, error correction codes (ECC) are widely used and play an important role. The main effect of ECCs is to reduce the transmission error caused by channel noise, thereby protecting data and increasing the quality of information transmission. In addition, high spectral efficiency is desired in...
We consider the problem of finding unknown patterns that are recurring across multiple sets. For example, finding multiple objects that are present in multiple images or a short DNA code that is repeated across multiple DNA sequences. We first consider a simple problem of finding a single unknown pattern in...
Quantum physics in the Copenhagen interpretation places an unsatisfying divide between the quantum and classical worlds. Decoherence -- the destruction of superposition states of the system -- helps us understand how the quantum transitions to the classical. Quantum Darwinism builds on decoherence to understand how information about the system is...
As computation power continues to grow, the demand for data transfer bandwidth is also rising. This is reflected in the increasing data-rate of high-speed links. However, the increase in data-rate is sustainable only if the I/O energy efficiency improves as well. This dissertation explores several techniques to enable high-speed links...
Continues-Time (CT) Delta-Sigma (ΔΣ) Analog-to-Digital Converters (ADCs) have one important constrain, namely the excess loop delay. Most previous excess lop delay compensation methods need to know the exact value of the excess loop delay in advance. However, the value of the excess loop delay is a uniformly distribution random variable....
The potential for electric energy generation from ocean waves is substantial and much research is being conducted on the conversion process as a renewable, grid-connected, power source. Some of the same attributes that make wave energy harvesting attractive as a grid-connected source also make it attractive as a remote, or...