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You searched for subject:(hard stabilization). Showing records 1 – 3 of 3 total matches.

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University of Arkansas

1. Dennis, John Chandler. Impacts of Hard Stabilization on the Shore of Yellowstone Lake, Yellowstone National Park, Wyoming, USA.

Degree: PhD, 2012, University of Arkansas

Discussions related to the adverse impacts associated with shore armor (i.e. seawalls and riprap) are a common topic within the coastal community. While many agree that the installation of these structures alters the shores geomorphic response, there is disagreement in the type and degree of response. Furthermore, studies that have delved into this topic have been conducted in numerous settings but have been confounded by a lack of data regarding shore morphologies prior to installation of these structures. At Yellowstone National Park, there is an opportunity to assess the impacts of shore armor quantitatively because the National Park Service requires detailed surveys in advance of all infrastructure improvement projects in an effort to determine the overall impacts of these projects on park environments relative to their benefits to park visitors and employees. The purpose of this study then was to contribute to this ongoing discussion of adverse impacts from shore armor by monitoring several non-engineered and engineered shore segments along the shore of Yellowstone Lake. For the purposes of this study, all shore segments that possessed shore armor (i.e. a seawall or riprap) were referred to as an engineered beach while any shore lacking a seawall or riprap was classified as a non-engineered shore segment. This study began with an effort to determine if there were geomorphic differences between several non-engineered and engineered shore segments located along the western and northern shore of Yellowstone Lake. This effort was accomplished by measuring cross-shore profiles, dry-beach widths and conducting a grain size analysis of the dry-beach sediments. Results from the initial survey conducted in July-August 2005 established that there were significant geomorphic differences between the non-engineered and engineered shore segments of Yellowstone Lake. Visual observations combined with surveyed cross-shore profiles, grain size analyses and dry-beach width measurements revealed that the non-engineered shore segments were indeed geomorphically different from the engineered segments. That is, the non-engineered shore segments displayed relatively wider beaches composed of sand to fine gravel with gently sloping profiles whereas the engineered shores were typified with angular L-shaped profiles with narrow dry-beach faces. In addition to the geomorphic differences, visual observations and analysis of the data revealed that the engineered shores were indeed adversely impacted by the shore armor through the processes of placement loss and profile deflation. A repeat survey was then conducted in the summers of 2006 and 2007 to determine the short-term variability of these non-engineered and engineered shore segments. Three years of data with a two-year interval indicated that there was a consistent difference in the geomorphology of the non-engineered and engineered shore segments. These differences were reflected in the cross-shore profile, the volume, and the dry beach width for all four study sites.… Advisors/Committee Members: Stephen K. Boss, Ralph K. Davis, John C. Dixon.

Subjects/Keywords: Earth sciences; Hard stabilization; Shoreline armor; Yellowstone lake; Yellowstone national park; Geology; Geomorphology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Dennis, J. C. (2012). Impacts of Hard Stabilization on the Shore of Yellowstone Lake, Yellowstone National Park, Wyoming, USA. (Doctoral Dissertation). University of Arkansas. Retrieved from https://scholarworks.uark.edu/etd/420

Chicago Manual of Style (16th Edition):

Dennis, John Chandler. “Impacts of Hard Stabilization on the Shore of Yellowstone Lake, Yellowstone National Park, Wyoming, USA.” 2012. Doctoral Dissertation, University of Arkansas. Accessed January 19, 2021. https://scholarworks.uark.edu/etd/420.

MLA Handbook (7th Edition):

Dennis, John Chandler. “Impacts of Hard Stabilization on the Shore of Yellowstone Lake, Yellowstone National Park, Wyoming, USA.” 2012. Web. 19 Jan 2021.

Vancouver:

Dennis JC. Impacts of Hard Stabilization on the Shore of Yellowstone Lake, Yellowstone National Park, Wyoming, USA. [Internet] [Doctoral dissertation]. University of Arkansas; 2012. [cited 2021 Jan 19]. Available from: https://scholarworks.uark.edu/etd/420.

Council of Science Editors:

Dennis JC. Impacts of Hard Stabilization on the Shore of Yellowstone Lake, Yellowstone National Park, Wyoming, USA. [Doctoral Dissertation]. University of Arkansas; 2012. Available from: https://scholarworks.uark.edu/etd/420


University of Georgia

2. Jackson, Chester W. Spatio-temporal analysis of barrier island shoreline change.

Degree: 2014, University of Georgia

Deficiencies exist in the study of shoreline dynamics of Georgia’s barrier islands and the processes that influence change. Previously unexamined shoreline localities that were difficult to assess using existing techniques and software programs provide a basis for the development of new tools and methods for analyzing change. AMBUR (Analyzing Moving Boundaries Using R) was developed to analyze shoreline change along barrier islands with complex shapes and highly curved coastlines. Built using the R programming environment, AMBUR provides a suite of functions for quantifying the rate and magnitude of shoreline movement and performs additional statistical, graphical, and geospatial analyses. The reliability of transect-based analyses is improved using new techniques for curved shorelines too problematic for the traditional perpendicular-transect method. Application of AMBUR to Georgia’s barrier islands provides a robust dataset for island-wide shoreline change and assists with classifying the modern behavior of the coast. Historical shorelines from 1855 to 2004 were analyzed and partitioned into oceanfront, backbarrier, and inlet-facing zones. Throughout the 1855 to 2004 era, 41 % of Georgia’s oceanfront shoreline eroded at a mean rate of -1.66 m/yr EPR (± 0.06 m/yr) and the remaining shoreline accreted at 2.25 m/yr EPR (± 0.06 m/yr). The backbarrier eroded along 65 % of the shore at a mean rate of -0.35 m/yr EPR (± 0.07 m/yr) throughout the period. More than half of the islands exhibit a net seaward shift in area and regressive behavior, whereas Wolf and St. Catherines Islands are thinning and shortening and are transgressive, erosional hotspots. Reversals of longshore transport currents, primarily due to inlet dynamics and seasonal shifts in climate regimes, promote periods of accretion and erosion along the northern and southern ends of some islands. Stable, migrating, and ephemeral inlet processes at the local level exert the greatest influence over oceanfront shorelines. Backbarrier shorelines are primarily influenced by tidal creek migration, proximity to inlets and confluences of other streams. Human activities are influencing shoreline erosion and accretion rates through uses of hard/soft stabilization and dredging activities.

Subjects/Keywords: shoreline change; oceanfront; backbarrier; inlet; coastal mapping; Holocene; Pleistocene; AMBUR; transect; baseline; erosion; accretion; t-sheets; aerial photography; endpoint rate; morphodynamics; anthropogenic; hard stabilization; storms; rivers; tidal

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Jackson, C. W. (2014). Spatio-temporal analysis of barrier island shoreline change. (Thesis). University of Georgia. Retrieved from http://hdl.handle.net/10724/26360

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Jackson, Chester W. “Spatio-temporal analysis of barrier island shoreline change.” 2014. Thesis, University of Georgia. Accessed January 19, 2021. http://hdl.handle.net/10724/26360.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Jackson, Chester W. “Spatio-temporal analysis of barrier island shoreline change.” 2014. Web. 19 Jan 2021.

Vancouver:

Jackson CW. Spatio-temporal analysis of barrier island shoreline change. [Internet] [Thesis]. University of Georgia; 2014. [cited 2021 Jan 19]. Available from: http://hdl.handle.net/10724/26360.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Jackson CW. Spatio-temporal analysis of barrier island shoreline change. [Thesis]. University of Georgia; 2014. Available from: http://hdl.handle.net/10724/26360

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

3. Mashrafi, Sheikh. X-ray microscope performance enhancement through control architecture change.

Degree: MS, 0133, 2014, University of Illinois – Urbana-Champaign

The goal of this thesis is to apply control algorithms to improve the performance of nanopositioning devices used on the beamline in Advanced Photon Source (APS) at Argonne National Laboratory (ANL). A prototype device, better known as the Early User Instrument (EUI) was the subject of this work. It consists of X-ray optics stage group that focuses the X-ray beam as a source-size-limited spot onto a sample held on the sample stage group. The controller algorithms that are used should provide the closed-loop with robust stability, large bandwidth, high resolution, disturbance rejection and noise attenuation. Conveniently, the field of scanning probe microscopes (SPMs) have already flourished on this aspect of controller algorithms proven to give desired closed-loop properties. Controller algorithms such as Proportional Integral Derivative (PID), Glover-McFarlane H-infinty algorithm, and 1DOF H-infinty controller were designed and implemented on the EUI system. The controller hardware used for implementation is National Instruments (NI) CompactRIO hardware that consists of a real-time controller, a FPGA built into the hardware chassis, analog I/O modules, and digital I/O modules. NI LabVIEW, the dedicated software to the NI hardware, was used to represent the discrete controllers as biquads structures that ran in the FPGA as a part of the closed-loop . The largest closed-loop bandwidth achieved is of 65 Hz through the 1DOF H-infinty controller and is a 171% improvement over the traditional PID controller. Highest closed- loop resolution achieved by the EUI with a 50 Hz bandwidth 1DOF H-infinty controller is 1.4 nanometers, which is a 180% improvement over the open loop resolution of 7 nanometers. Advisors/Committee Members: Salapaka, Srinivasa M. (advisor), Preissner, Curt (advisor).

Subjects/Keywords: control; Control Architecture; Advanced Photon Source (APS); Argonne National Laboratory (ANL); control algorithms; nanopositioning; nanopositioning devices; Early User Instrument (EUI); X-ray; optics; robust stability; bandwidth; resolution; disturbance rejection; noise attenuation; scanning probe microscope (SPM); closed-loop properties; Proportional Integral Derivative (PID); Glover-McFarlane h-infinity algorithm; 1DOF h-infinity controller; h-infinity; Glover-McFarlane controller; Keith Glover; Duncan McFarlane; controller; controller implementation; National Instruments (NI); CompactRIO; real-time controller; Field-Programmable Gate Array (FPGA); LabVIEW; biquads structures; closed-loop bandwidth; U.S. Department of Energy (DOE); Office of Science; DE-AC02-06CH11357; DE-SC0004283; Cross Power Spectral Density (CPSD); Power Spectral Density (PSD); Degree Of Freedom (DOF); Discrete-Time Fourier Transform (DTFT); Hardware Description language (HDL); High-Level Synthesis (HLS); Hard X-ray Nanoprobe (HXN); In Situ Nanoprobe (ISN); Laser Doppler Displacement Meter (LDDM); Physik Instrumente (PI); Reconfigurable Input/Output (RIO); Advanced Photon Source (APS) beamline; full-field imaging microscopy; fluorescence mapping; nanodiffraction; transmission imaging; reliability and repeatability of positioning systems; modeling uncertainties; insensitive modeling uncertainties; quantifying trade-offs; trade-offs; design flexibility; design methodology; feedforward; feedback; performance objectives; robustness; Advanced Photon Source (APS) user; beamline scientist; imaging resolution and bandwidth; imaging resolution; nanoprobe; model fitting; curve fitting; model reduction; feedback controllers; X-ray nanoprobe instrument; third-generation synchrotron radiation source; zone plate optics; zone plate; flexure stages; piezoelectric actuators stacks; flexure; Piezoelectric; high-stiffness stages; high-resolution weak-link stages; piezoelectric-transducer; sub-nanometer resolution; subnanometer; optical heterodyning; heterodyning; Optodyne; frequency-shifted laser beam; PID controller; digital to analog converter (DAC); analog input modules; digital input modules; analog output modules; cRIO-9118; Virtex-5; Virtex-5 LX110 FPGA chassis; NI-9223; NI-9402; NI-9263; System Identification; Identification; black-box identification; parametric model; non-parametric model; welch; pwelch; tfestimate; invfreqs; time domain data; band-limited uniform Gaussian white noise; band-limited; white noise; resonant peak; Balance Realization; minimal realization; controllability; observability; Experimental Frequency response; transfer function; Hankel singular values; Hankel norm; balanced truncation; noise histogram; Open Loop Resolution; closed Loop Resolution; Simulink simulation; LabVIEW simulation; discrete controller; continuous controllers; discrete; Tustin; tustins method; discretization; complementary sensitivity transfer function; sensitivity transfer function; robust stabilization; coprime factorization; Bezout identity; Bezout; stability margin; algebraic Riccati equation; Riccati equation; sub-optimal; suboptimal; sub-optimal controller; optimal controller; mixed-sensitivity optimization; sensitivity optimization; generalized framework; generalized controller framework; stabilizing controller; closed-loop objectives; generalized plant; nominal plant; linear fractional transformation; weighting transfer functions; weighted sensitivity; hinfsyn; bode integral law; waterbed effect; second waterbed formula; Skogestad; Poslethwaite; sensitivity weighting; sensitivity weighting transfer function; nanopositioner; nanopositioning device; nanopositioning system; second order sections; ASPE 28th Annual Meeting; American Society for Precision Engineering (ASPE); Synchrotron Radiation Instrumentation; Synchrotron; Nanoprobe Instrument

…Robust stabilization of a family of perturbed plants [12, 16]. . . . . . . . . A… …HDL Hardware Description Language HLS High-Level Synthesis HXN Hard X-ray Nanoprobe… …device design is based on the prototype for the hard X-ray nanoprobe (HXN) [6, 9… …will be readily and effectively applicable to the Hard X-ray nanoprobe and other similar X… …named EUI, which is a prototype of the APS hard X-ray nanoprobe instrument. EUI was developed… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Mashrafi, S. (2014). X-ray microscope performance enhancement through control architecture change. (Thesis). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/46671

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Mashrafi, Sheikh. “X-ray microscope performance enhancement through control architecture change.” 2014. Thesis, University of Illinois – Urbana-Champaign. Accessed January 19, 2021. http://hdl.handle.net/2142/46671.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Mashrafi, Sheikh. “X-ray microscope performance enhancement through control architecture change.” 2014. Web. 19 Jan 2021.

Vancouver:

Mashrafi S. X-ray microscope performance enhancement through control architecture change. [Internet] [Thesis]. University of Illinois – Urbana-Champaign; 2014. [cited 2021 Jan 19]. Available from: http://hdl.handle.net/2142/46671.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Mashrafi S. X-ray microscope performance enhancement through control architecture change. [Thesis]. University of Illinois – Urbana-Champaign; 2014. Available from: http://hdl.handle.net/2142/46671

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.