An understanding of natural coastal hazards is essential for improving resilience of coastal communities. Effective management of coastal hazards relies on prediction tools and mitigation structures that have been designed to handle the dynamic coastal system. This dissertation is a collection of manuscripts that cover a diverse range of fundamental...
To better understand the extreme local amplification of tsunami, the experimental investigation on counter-propagating solitary wave collisions over a horizontal bottom was conducted using the optical measurement techniques: Particle Image Velocimetry (PIV), and Laser Induced Fluoresce (LIF). Head-on collisions and oblique collisions of equal-amplitude as well as unequal-amplitude waves were...
Soil instability from tsunami hazards causes substantial damage to coastal infrastructure (e.g., the damage caused by the 2011 Great East Japan Tsunami, or the Heisei Tsunami). Tsunamis are unpredictable, so it is difficult to obtain field-scale measurements. Simulating tsunamis in a laboratory setting is therefore important to further understanding of...
Reflection of an obliquely incident solitary wave at a vertical wall is studied experimentally in the laboratory wave tank. Precision measurements of water-surface variations are achieved with the aid of laser-induced fluorescent (LIF) technique and detailed temporal and spatial features of the
Mach reflection are captured. During the development stage...
Numerical results are presented using a higher-order pseudo-spectral method in order to solve the Zakharov-Craig-Sulem formulation of the Euler model. We study the effects of variable bathymetry on weakly-dispersive, weakly-nonlinear, shallow water waves. Improved predictions on wave amplitude and shoaling behavior are developed by analytical means in the context of...
Wave runup is an important physical process that affects nearshore sediment transport, coastal erosion, and flooding. Large and unexpected runup events can also be dangerous to beach goers. Extreme runup statistics are essential parameters used in engineering design of marine structures and in coastal management. Although the study of runup...
The understanding and prediction how coastal wetland vegetation attenuates wave action has received renewed attention with global climate change impacts and increasing populations on coastlines. Conventional attenuation models utilize empirical drag coefficients, but these coefficients exhibit a wide range of values, and there is some uncertainty in the relative importance...
This dissertation has focused on the charateristics of bubbles generated by breaking waves and the feedback of wave-current interaction on the forcing mechanism of low frequency wave especially basin seiching wave. For the first study, Optical image capture observations of breaking waves in a laboratory surf zone are presented. The...
We describe spatio-temporal random processes using linear mixed models and discuss estimation, inference, and prediction under this formulation. We show how many commonly used covariances are special cases of this more general framework and pay special attention to the separable and product-sum covariances. The linear mixed model formulation facilitates straightforward...
A sewer geyser is a series of ejecting air-water mixture eruptions through vertical shafts of drainage systems. In field observed geyser incidents, manhole covers were blown into the air and they were followed by ejecting air-water mixture eruptions that lasted for several seconds at a time. Trapped air in sewer...
Machine learning systems are generally trained offline using ground truth data that has been labeled by experts. However, these batch training methods are not a good fit for many applications, especially in the cases where complete ground truth data is not available for offline training. In addition, batch methods do...
This thesis contains three parts addressing the asymptotic analysis of fluid flow through fully saturated porous medium in the presence of an adjacent thin channel.
In the first part the problem is modeled by Darcy's law in both the porous medium and in the channel. The permeability in the channel...
Fluid-structure interaction (FSI) is a very interesting and challenging multi-disciplinary field involving interaction of a movable or deformable structure with an internal or surrounding fluid flow. FSI has several practical engineering applications such as the determination of the hydrodynamic forces on a structure or the dynamics of motion of bodies...
The safety of coastal infrastructure has been a concern after the Indian Ocean Tsunami in 2004 and the Great East Japan Tsunami in 2011. The western coast of the United States is also exposed to tsunami hazards due to the Cascadia subduction zone. Therefore, it is critical to design coastal...
Sediment convergence and divergence zones create subaqueous morphological features that range from ripples O (cm) to coastlines O (km). However, there is a gap in knowledge associated with quantifying the contribution of small-scale ripple mobility to the evolution of large-scale morphology. To address this gap, we investigate how small-scale ripples...
The coastal region is home to many types of surface fronts that exist on a submesoscale (1-10 $km$). While in situ observations capture point or transect observations of frontal behavior subsurface, their complex spatial patterns can be well-captured using remote sensing techniques, which provide synoptic views of the ocean surface...
This thesis considers the problem in which a teacher is interested in teaching action policies to computer agents for sequential decision making. The vast majority of policy
learning algorithms o er teachers little flexibility in how policies are taught. In particular,
one of two learning modes is typically considered: 1)...
The exchange of carbon on earth is one of the fundamental processes that sustains life and regulates climate. Since the onset of the Industrial Revolution, the burning of fossil fuels and anthropogenic land conversion have altered the carbon cycle, increasing carbon dioxide in the atmosphere to levels that are unprecedented...
Wave breaking in the surf zone is an important forcing
mechanism on the generation of nearshore currents and in the driving
of sediment transport. At the same time, wave breaking can have
significant spatial and temporal variability that needs to be
accounted for in the description of nearshore processes. Remote...
In many traditional computer graphics applications, rendered scenes typically utilize 3D meshes to represent objects within an environment. As the demand to further improve the realism of graphics applications increases, such as for movies and games, it is becoming more important to represent the inner volumes of object meshes. In...
In real networks, identifying dense regions is of great importance. For example, in a network that represents academic collaboration, authors within the densest component of the graph tend to be the most prolific. Dense subgraphs often identify communities in social networks. And dense subgraphs can be used to discover regulatory...
Tsunami loading can cause sediment instability, which can compromise the structural integrity of coastal buildings and infrastructure. To understand the process by which a tsunami can cause sediment instability, it is necessary to understand how the pore water pressure in the soil changes during tsunami loading. Tsunami run-up causes the...
Networks of distributed, remote sensors are providing ecological scientists with a view of our environment that is unprecedented in detail. However, these networks are subject to harsh conditions, which lead to malfunctions in individual sensors and failures in network communications. This behavior manifests as corrupt or missing measurements in the...
The objective of this work was to define the effects of
dietary energy intake on broiler fat deposition and
metabolism. Fatty broilers are one of the major problems in
the broiler industry.
The effects of changing calorie to protein (Cal/Pr)
ratios, and the addition of cellulose or dried distiller's byproduct...
Coastal multi-hazards, i.e., earthquakes followed by tsunamis, induce severe damage to coastal infrastructure. The multi-hazards can cause soil liquefaction, which is one of the major concerns for evaluating sediments transport potential and structure failure mechanisms. The objectives for this work is threefold. First, to build and validate a soil numerical...
Most data are associated with a place, and many are also associated with a moment in time, a time interval, or another linked temporal component. Spatiotemporal data (i.e., data with elements of both space and time) can be used to assess movement or change over time in a particular location,...
Damage estimates to the built environment from tsunamis are important for disaster mitigation, including planning emergency response and recovery. This dissertation evaluates the damage states of buildings in a small urban coastal city, Seaside, Oregon, from tsunami hazards generated by a Cascadia Subduction Zone (CSZ) event. This study is separated...
Despite the advances in surgery, physical therapy, and pharmaceutical agents, muscle
dysfunction (i.e., atrophy and weakness) continues to impair recovery from an anterior
cruciate ligament (ACL) injury and surgery. Ischemia-reperfusion injury during surgery
and the subsequent limb disuse are two events experienced by patients having ACL
surgery. Oxidative stress and...
The advent of deep learning models leads to a substantial improvement in a wide range of NLP tasks, achieving state-of-art performances without any hand-crafted features. However, training deep models requires a massive amount of labeled data. Labeling new data as a new task or domain emerges consumes time and efforts...
The dissertation focuses on the engineering of light-matter interaction using plasmonic nanoparticles and metamaterials to achieve enhanced luminescence and based on which to improve the performance of biosensing and light-emitting technologies. We designed and fabricated a spectrum of nanostructures to exhibit particular dispersion relations capable of controlling the spontaneous emission...
The purpose of this study was to explore and describe
the attitudes and preferences regarding home/school
involvement strategies of 23 mothers of kindergarten
students who had been identified as at-risk for failure in
school and 18 mothers of kindergarten students who had been
designated as peer models.
Data were collected...
Proper use of vegetation in streambank bioengineering practices requires a comprehensive understanding of the influence of vegetation density on streambank hydraulics. A series of studies were conducted to investigate the relationship between independent variables vegetation density, bank angle, and discharge and dependent variables channel velocity, resistance, turbulence, and shear stress....
Discussions around adapting water management systems to climate change often express the need to increase the flexibility and adaptive capacity of current systems, and to implement robust strategies going forth. While these topics lie at the center of many climate change discussions, transforming adaptation recommendations into tangible tools and information...
American meteorology was synonymous with subjective weather forecasting in the early twentieth century. Controlled by the Weather Bureau and with no academic programs of its own, the few hundred extant meteorologists had no standing in the scientific community. Until the American Meteorological Society was founded in 1919, meteorologists had no...
Two indigenous species of burrowing shrimp inhabit and often dominate the intertidal zone of estuaries along the US West Coast, the ghost shrimp, Neotrypaea californiensis, and the blue mud shrimp, Upogebia pugettensis. Both species are considered ecosystem engineers and play a role in maintaining estuarine health and ecosystem function. They...
Many applications in computer graphics and geometry processing rely on the ability to
locally orient 2D and 3D entities on a surface, or inside a volume, such as the sinusoidal
kernels in Gabor noise, the color and geometry textures in pattern synthesis, and the
finite elements in remeshing. In these...
Analysis, visualization, and design of vector fields on surfaces have a wide variety of major applications in both scientific visualization and computer graphics. On the one hand, analysis and visualization of vector fields provide critical insights to the flow data produced from simulation or experiments of various engineering processes. On...
The U.S. Pacific Northwest is home to one of the most extreme wave climates in the world with waves of 10 m in height arriving to the coast approximately each year. With an average water temperature of 12℃, the beaches in the region are too cold to go on a...
In this dissertation the interactions between hydrodynamics, sediment suspension and transport, and morphological evolution in the surf zone was investigated with a large-scale laboratory experiment data, CROss-Shore Sediment Transport Experiment (CROSSTEX). The data set included comprehensive measurements of water surface elevation, fluid velocity, sediment concentration, and morphology for irregular waves...
Little research has been done in the area of adult Hispanics' transition to college, a complex and challenging process which marks a critical period in their lives. Research suggests adaptation difficulty may cause them to drop out of school usually before completion of the first terms. There is a lack...
Ph.D. candidate Qi Wei's thesis consists of two projects: Chemotherapy Project: a study based on the research paper "Predicting chemotherapy response of various cancer types using a variational auto-encoder approach" submitted to the bioRxiv preprint archive and accepted by the BMC bioinformatics; and Wound Monitor Project: implementing and assessing analytics...
Plant pathogenic Rhodococcus species are persistent pathogens able to cause severe growth deformities on a large range of hosts. The most well studied species, R. fascians is predicted by current models to synthesize a mixture of cytokinins that act to directly perturb the hosts' hormone balances, which results in abnormal...