Index Catalog // ScholarsArchive@OSU

Data Assimilation using Synthetic-Aperture Radar Imagery for Bathymetry Inversion at the Mouth of the Columbia River

Creator:: Harper, Spencer H.
Abstract:: Synthetic-aperture radar (SAR) imagery can provide wavenumber and frequency data to generate bathymetry estimates for locations where limited access or extreme ocean conditions can make standard bathymetry survey techniques difficult or impossible. The availability of SAR data could allow for regular bathymetry estimates of navigational channels providing insight into dredging...
Resource Type:: Masters Thesis
Full Text:: River. Abstract approved:_____________________________________________________ H. Tuba Özkan

Toward wave energy in Oregon : predicting wave conditions and extracted power

Creator:: Oskamp, Jeffrey A.
Abstract:: Knowledge of wave conditions in nearshore regions supports the development of ocean wave energy technology by providing wave climatology for device design considerations, and power output estimates. By modeling wave transformation over the continental shelf, wave conditions were predicted in nearshore regions where potential wave energy conversion sites are located....
Resource Type:: Masters Thesis
Full Text:: would like to thank my advisor, Dr. H. Tuba Özkan-Haller, for the time she spent working with me on

Modeling shallow-water hydrodynamics : rotations, rips, and rivers

Creator:: Long, Joseph W.
Abstract:: Hydrodynamic models are used as a diagnostic tool to understand the temporal variability of shallow-water processes that are difficult to completely resolve with traditional field measurements. For all simulations, modeled quantities are qualitatively or quantitatively compared with available measurements to gain confidence in conclusions derived from the modeled results. In...
Resource Type:: Dissertation
Full Text:: -Water Hydrodynamics: Rotations, Rips, and Rivers Abstract approved: H. Tuba Özkan-Haller

Wave field patterns generated by wave energy converters

Creator:: McNatt, J. Cameron
Abstract:: The eventual deployment of wave energy converters (WECs) on a commercial scale will necessitate the grouping of devices into arrays or "wave farms," in order to minimize overhead costs of mooring, maintenance, installation, and electrical cabling for shoreward power delivery. Closely spaced WECs will interact hydrodynamically through diffracted and radiated...
Resource Type:: Masters Thesis
Full Text:: Patterns Generated by Wave Energy Converters Abstract approved: H. Tuba Özkan-Haller The eventual

Wave propagation processes at the mouth of the Columbia River

Creator:: Andes, Lisa (Lisa Christine)
Abstract:: The mouth of the Columbia River (MCR) has a longstanding reputation of hazardous navigational conditions. This reputation has been developing since the first ship, the Columbia, traversed through the inlet in 1792. The hazardous conditions are related to the large waves and strong tidal currents that are common in the...
Resource Type:: Masters Thesis
Full Text:: ()"Nj]�!$23 Q Q�Q Q�Q�Q Q Q�Q Q Q�Q�Q Q Q�Q Q Q�Q�Q Q Q�Q Q Q�Q�Q Q &.H �2Q!GNQ5� �<�! 1;4F� 1 1�S+?$Q

Power Output Calculations for an Array of Point-absorber Wave Energy Converters

Creator:: García-Castaño, Manuel
Abstract:: This study presents a methodology for power take off (PTO) forecasting for an array of heave wave energy converters (WECs). Based on spectral data obtained directly from the National Data Buoy Center, representative realistic sea states are generated at the location of the WECs, and by using two wave-structure interaction...
Resource Type:: Masters Thesis
Full Text:: : ____________________________________________________________________ H. Tuba Özkan-Haller This study presents a methodology for power take off (PTO) forecasting

Weather and large waves along the Oregon coast: atmospheric controls on a numerical wave model

Creator:: Ellenson, Ashley N.
Abstract:: In this study, the effects of implementing different wind input or physics packages in a numerical wave model to recreate large wave conditions are explored. Three large wave events are simulated with WaveWatch III. The wind inputs which are compared are NCEP's Global Forecasting System (GFS) with 0.5 degree resolution...
Resource Type:: Masters Thesis
Full Text:: acknowledge my committee members, H. Tuba Özkan-Haller, Jim Thomson, and Merrick Haller for their guidance

Large-scale laboratory observations of wave breaking turbulence on a fixed barred beach

Creator:: Scott, Christopher P.
Abstract:: This thesis presents the details of a large-scale laboratory experiment to study the turbulence generated by waves breaking on a fixed barred beach. The data set includes comprehensive measurements of free surface displacement and fluid velocity for one random and one regular wave case. Observations of the time-averaged turbulent kinetic...
Resource Type:: Masters Thesis
Full Text:: questions and encouragement from my cont mnbers, avtkic Hailer and Tuba kan-Hailer, are much appreciated

Nowcast/forecast of storm surge and drawdown using a hybrid FE/ANN approach

Creator:: Darnell, Joel T.
Abstract:: In the northwestern Gulf of Mexico there is a need for reliable water level forecasts to facilitate safe commercial navigation, marine construction, and emergency management. Though the low amplitude tides of the region can be predicted with conventional harmonic techniques, frequent strong storms make accurate forecasts of water levels difficult....
Resource Type:: Masters Thesis
Full Text:: last 4 years and my committee members, Dr. Merrick Hailer and Dr. Tuba Ozkan-Haller, for their

Remote sensing of radiation stress gradients from optical imagery

Creator:: Killian, Jason R.
Abstract:: Wave-induced circulation is the defining characteristic of the nearshore. Within this region, the constant feedback cycle between incoming waves, wave-generated currents, and the mobile sediment bed is responsible for the evolution of complex patterns in nearshore and beach morphology. Central to our understanding of this system is knowledge of the...
Resource Type:: Masters Thesis
Full Text:: help me finish this project, and my committee members, Mick Haller and Tuba Özkan-Haller, for their

Remote measurements of waves and currents over complex bathymetry

Creator:: Chickadel, Carmine C. (Carmine Christopher)
Abstract:: Waves are the primary input of energy in the nearshore region, and together with the currents forced through the transfer of momentum that occurs during the wave breaking process they are the principal mechanism for sediment transport in the nearshore. The basic physics of waves and currents are thought to...
Resource Type:: Dissertation
Full Text:: committee members, Tuba Ozkan-Haller for her incredible ability to teach even me, Mick Haller for his

Development of 2D models to estimate nearshore bathymetry and sediment transport

Creator:: Splinter, Kristen D.
Abstract:: We examine the interactions and feedbacks between bathymetry, waves, currents, and sediment transport. The ﬁrst two pro jects focus on the use of remote sensing techniques to expand our knowledge of the nearshore. Due to the plethora of snap-shot data that is available from satellites and their distribution via Google...
Resource Type:: Dissertation
Full Text:: , 2DH bar variability, a, and wave characteristics (wave height, H, wave period, T , and wave angle, θ

Laboratory observations and numerical modeling of inner surf and swash zone hydrodynamics on a steep slope

Creator:: Shin, Sungwon
Abstract:: Laboratory data of free surface elevations and fluid velocities were obtained using a laser-Doppler velocimeter for the case of a periodic wave plunging over an impermeable, steep (1:10) slope with a fixed bottom roughness. The measurements were conducted over 15 cross-shore locations from the outer surf zone to the swash...
Resource Type:: Dissertation
Full Text:: and advice. I am thankful to Dr. Solomon Yim, Dr. Memck Haller, Dr. Tuba Ozkan- Hailer, and Dr. Ben

Observations on the evolution of shoaling nonlinear internal waves in Massachusetts Bay using shipboard X-band radar

Creator:: Nelson, Brian G.
Abstract:: During four cruises in July and September of 2008 and 2009, the shipboard X-band radar was tuned to detect the modulated bands of surface roughness caused by converging and diverging currents associated with high-frequency nonlinear internal wave (NLIW) packets. The data collected was used to quantify the propagation direction (ϴp),...
Resource Type:: Masters Thesis
Full Text:: Beam Width (H): 1.23 dgrs Frequency: 9.410gHz ± 0.030 gHz Beam Width (V): 20 dgrs TR Unit: RTR-079

Evaluation of Stereoscopic Camera Systems for Non-Intrusive Spatial Free Surface Measurement in Coastal Research Laboratories

Creator:: O'Day, Christopher S.
Abstract:: Physical modelling is instrumental to the progression of coastal engineering research and our understanding of the offshore and nearshore environments. Scaled models are designed and built to be tested in coastal research laboratories, where a wave basin or flume generates the desired wave conditions for experimentation. The surrounding hydrodynamics of...
Resource Type:: Masters Thesis
Full Text:: ............................................................................................................... 87 6.1.1 Shore Normal (H = 0.5 m, T = 1.8 s, θ = 0 deg, h= 1m

Evaluation of the performance of a taut-moored dual-body direct-drive waveenergy converter through numerical modeling and physical testing

Creator:: Elwood, David E.
Abstract:: With energy prices rising and increasing concern about the influence of fossil fuels on climate change, wave energy systems are on the verge of commercial implementation. These first generation wave energy converters utilize either pneumatics or hydraulics to convert the mechanical energy of waves into electricity. For the last several...
Resource Type:: Masters Thesis

Coastal sand dunes in the U.S. Pacific Northwest : regional variability in foredune geomorphology and associated physical vulnerability to hazards

Creator:: Mull, Jeremy M.
Abstract:: Coastal foredunes protect lives, infrastructure, and ecosystems during severe winter storms. In the U.S. Pacific Northwest (PNW), coastal foredune geomorphology is determined by both physical and ecological mechanisms. Before the 1900's, the native plant Elymus mollis was the dominant dune grass and dune morphology was largely determined by sediment supply...
Resource Type:: Masters Thesis
Full Text:: Merrick Haller and David Hill. Their advice on specific analyses and reviews of this document were

Numerical and Analytical Modeling of Temperature Evolution in Laser Processing of Materials

Creator:: Ball, Stefan R.
Abstract:: The ultimate goal of this work is to analyze and compare two predictive models of thermal profile in laser processing of materials. An analytical method that uses closed-form equations to represent a geometric model of a laser heat source will be contrasted with a commercial computational fluid dynamics code that...
Resource Type:: Masters Thesis
Full Text:: speed of the heat source to the medium, 𝑇 is temperature, 𝜌 is density, 𝑘 is conductivity, ℎ is

Contact and impact dynamic modeling capabilities of LS-DYNA for fluid-structure interaction problems

Creator:: Challa, Ravi
Abstract:: 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 plays a pivotal role in many different types of real-world situations and practical engineering applications involving large structural deformation and material or geometric...
Resource Type:: Masters Thesis
Full Text:: thankful to Prof. Harry Yeh and Prof. Merrick Haller for imparting the basic principles in ocean

Predicting deep water breaking wave severity

Creator:: Hovland, Justin
Abstract:: Ocean Wave Energy Converters (WECs) operating on the water surface are subject to storms and other extreme events. In particular, high and steep waves, especially breaking waves, are likely the most dangerous to WECs. A method for quantifying the breaking severity of waves is presented and applied to wave data...
Resource Type:: Masters Thesis
Full Text:: of gravity (m/s2) h Water depth (m) H Wave height (m) Hm0 Spectrally derived significant wave

Wave Resource Assessments: Spacio-Temporal Effect of Wave Energy Converter Scale and Blue Economy Opportunities

Creator:: Dunkle, Gabrielle R.
Abstract:: Wave energy has the potential to power large and small factions of economies around the world alike. Current methods for determining the amount of wave energy resource available to wave energy converter (WEC) devices entail capturing the look of the sea state at large by presenting characteristic wave heights, periods,...
Resource Type:: Masters Thesis
Full Text:: thank my committee members Dr. Meagan Wengrove, Dr. Merrick Haller, and Dr. Edward Dever for their

Morphodynamic Evolution of Coastal Oregon: Using New Lidar-derived Beach and Sand Dune Morphometrics to Explore Multi-decadal Change

Creator:: Light, Jacob W
Abstract:: The coast of Oregon is highly dynamic, with beach and dune morphodynamics constantly evolving in response to physical and ecological forcing at scales ranging from seconds to decades and meters to tens of kilometers. Evaluating spatial and temporal trends in shoreline evolution is paramount in understanding and eventually developing a...
Resource Type:: Masters Thesis
Full Text:: committee members Dr. Merrick Haller, Dr. Meagan Wengrove, and Dr. Rick Colwell for their support and

Application of Motion Capture Technologies to Assess the Free Surface and Track Waterborne Debris in Wave Research Laboratories

Creator:: Shultz, Jamie
Abstract:: In coastal and ocean engineering, understanding the ocean environment and the forces from waves, tsunamis and waterborne debris on structures and floating bodies is an important aspect of designing safe and effective infrastructure. Understanding the impact of these forces on structures becomes an important question in the design process. Answering...
Resource Type:: Masters Thesis
Full Text:: A and B value, the wave height calculated from the B value, and kh and h calculated from this wave

Development of a Cartesian-grid-based solver for an oscillatory boundary layer over a rough wall

Creator:: Skitka, Joseph M.
Abstract:: Predominant models for predicting rates of sediment transport face acute shortcomings when applied to coastal boundary layers. This is due to a neglect of the web of stochastic variables governing the rate of sediment dislodgement. While stochastic models do exist, the parametric extent of their validity tends to be limited,...
Resource Type:: Masters Thesis
Full Text:: , my labmates Chaitanye Ghodke and Justin Finn, my masters thesis committee: Dr. Merrick Haller, Dr

Gaussian random fields related to Lévy's Brownian motion : representations and expansions, Gaussian random fields related to Levy's Brownian motion : representations and expansions

Creator:: Rode, Erica S.
Abstract:: This dissertation examines properties and representations of several isotropic Gaussian random fields in the unit ball in d-dimensional Euclidean space. First we consider Lévy's Brownian motion. We use an integral representation for the covariance function to find a new expansion for Lévy's Brownian motion as an infinite linear combination of...
Resource Type:: Dissertation
Full Text:: ,d 1 X m,k=0 ⇤ m,k,p (|t|) h(m) X j=1 ' m,j (t/|t|)Z m,k,j where ⇤ m,k,p is a function of

Sub-diffraction light propagation and imaging in planar negative refraction waveguides

Creator:: Wangberg, Robyn
Abstract:: In this dissertation we study the electromagnetic properties of planar waveguides with non-magnetic strongly anisotropic dielectric cores. We develop an analytical description of the mode propagation in these systems and show that the index of refraction can be either positive or negative depending on the specific material parameters. Propagating modes...
Resource Type:: Dissertation
Full Text:: left-handed relationship between �E, �H, and �k. . . . . . . . . . . . . . . . . . . . 15 2.2 Exact

Exchange interaction studies in magnetic semiconductors by neutron scattering

Creator:: Wiren, Zachary Quincy
Abstract:: Theories predict that making a dilute magnetic semiconductor strongly p -type would allow it to remain ferromagnetic at room temperature. This is of intrest as a ferromagnetic semiconductor would allow for a great many applications in the field of spintronics. Neutron scattering experiments were undertaken to better understand the antiferromagnetic...
Resource Type:: Dissertation
Full Text:: Haller, Henri Jansen, Yun-Shik Lee, Oksana Ostroverkhova, Guenter Schneider, and Phil Siemens. TABLE

DNS study of Particle-bed-Turbulence Interactions in Oscillatory Flows

Creator:: Ghodke, Chaitanya Deepak
Abstract:: Turbulent flows over rough surfaces are encountered in many engineering and geophysical applications. Flows of this nature, due to their increasing technological interests, have been a subject of rigorous investigation in recent years. Of the particular interest to the oceanographic community is the study of turbulent oscillatory flow over rough...
Resource Type:: Dissertation
Full Text:: , Prof. Chad Higgins and Prof. Merrick Haller for taking the time out to read this thesis, evaluate and

Mapping Nearshore Bathymetry with Spaceborne Data Fusion and State Space Modeling

Creator:: Forfinski-Sarkozi, Nicholas A.
Abstract:: Despite numerous techniques for measuring and estimating water depth, bathymetry in the nearshore zone is notoriously difficult to map. Dangerous sea states, noisy environmental conditions, and expensive survey operations, particularly in remote areas, contribute to the difficulties of obtaining data along the coast. Global datasets, derived mainly from satellite altimetry...
Resource Type:: Dissertation
Full Text:: mentor. I would also like to thank my committee members, Dr. Michael Olsen, Dr. Merrick Haller, Dr

Design techniques for delta sigma modulators using VCO based ADCs

Creator:: Reddy, Karthikeyan
Abstract:: VCO-based ADCs have recently emerged as attractive alternative to conventional DeltaSigma (ΔΣ) modulator architectures. Few salient features of a VCObased ADC are: 1) the quantization noise is 1st order noise shaped, 2) it is an open loop architecture, and, 3) its implementation is mostly digital in nature. Hence, they are...
Resource Type:: Dissertation
Full Text:: being my committee members. I would also like to thank Prof. Merrick Haller for being my Graduate

Practitioner’s hands and academic eyes : a practical approach to improving disaster preparedness and response

Creator:: Thompson, Wiley C.
Abstract:: This dissertation primarily uses observations made during the 2005 Kashmir earthquake relief effort and available disaster literature to address problems that impede effective and efficient disaster preparedness and response. Three manuscripts form the body of the dissertation. The manuscripts are thematically linked through the Emergency Management Cycle. Each manuscript examines...
Resource Type:: Dissertation
Full Text:: . Merrick Haller. I appreciate the support and guidance you all have shown. Each of you has contributed

Learning based methods applied to the MAV control problem

Creator:: Salichon, Max
Abstract:: This thesis addresses Micro Aerial Vehicle (MAV) control by leveraging learning based techniques to improve robustness of the control system. Applying classical control methods to MAVs is a difficult process due to the complexity of the control laws with fast and highly non-linear dynamics. These methods are mostly based on...
Resource Type:: Dissertation
Full Text:: Robert Paasch, Dr Mike Bailey, and Dr Merrick Haller for their time and patience throughout this

Application of Nonlinear Model Predictive Controller for Ocean Wave Energy Conversion Systems

Creator:: Haider, Ali S.
Abstract:: This work addresses the application of Nonlinear Model Predictive Control (NMPC) to a class of ocean wave energy conversion systems in which the cost functional is not in a standard quadratic form, and the WEC model includes the nonlinear effects, such as the hydrodynamic viscous drag. The NMPC implementation is...
Resource Type:: Dissertation

Navigation and coordination of autonomous mobile robots with limited resources

Creator:: Knudson, Matthew D.
Abstract:: The use of autonomous robots in complex exploration tasks is rapidly increasing. Indeed, robots can provide speed and cost effectiveness in many tasks, as well as allow operation in environments that are hostile to humans. In this dissertation we: 1) provide two adaptive navigation algorithms; 2) develop a coordination mechanism;...
Resource Type:: Dissertation

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