1,710 research outputs found
Automated, objective texture segmentation of multibeam echosounder data - Seafloor survey and substrate maps from James Island to Ozette Lake, Washington Outer Coast
Without knowledge of basic seafloor characteristics, the ability to address any number of critical marine and/or coastal management issues is diminished. For example,
management and conservation of essential fish habitat (EFH), a requirement mandated by federally guided fishery management plans (FMPs), requires among other things a
description of habitats for federally managed species. Although the list of attributes important to habitat are numerous, the ability to efficiently and effectively describe many, and especially at the scales required, does not exist with the tools currently available. However, several characteristics of seafloor morphology are readily obtainable at multiple scales and can serve as useful descriptors of habitat. Recent advancements in acoustic technology, such as multibeam echosounding (MBES), can provide remote indication of surficial sediment properties such as texture, hardness, or roughness, and further permit highly detailed renderings of seafloor morphology. With acoustic-based surveys providing a relatively efficient method for data acquisition, there exists a need for
efficient and reproducible automated segmentation routines to process the data. Using MBES data collected by the Olympic Coast National Marine Sanctuary (OCNMS), and
through a contracted seafloor survey, we expanded on the techniques of Cutter et al. (2003) to describe an objective repeatable process that uses parameterized local Fourier
histogram (LFH) texture features to automate segmentation of surficial sediments from acoustic imagery using a maximum likelihood decision rule. Sonar signatures and
classification performance were evaluated using video imagery obtained from a towed camera sled. Segmented raster images were converted to polygon features and attributed
using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999) for use in a geographical information system (GIS). (PDF contains 41 pages.
Minding the Gap: Pay Equity and the Role of Law in Narrowing Canada\u27s Gender Wage Gap
Canada has a gender wage gap. Gender discrimination is one of the factors underlying that gap. The goal of this thesis is to determine if Canadian law can be used to narrow the gender wage gap and if so, what legal reforms should be made? To meet these ends this thesis examines the evolution of relevant Canadian human rights and pay equity law and makes comparisons between the types of laws specific jurisdictions use and the size of their respective gender wage gaps. The focus then shifts to laws enacted in foreign jurisdictions that Canada could adopt to further address the gender discrimination underlying the gap. Ultimately, this thesis argues that Canadian law can be reformed to narrow the gender wage gap by first, widening the applicability of pay equity law among jurisdictions and workforce sectors and second, compel employer compliance through complimentary legislation such as pay transparency laws
First-order sidebands in circuit QED using qubit frequency modulation
Sideband transitions have been shown to generate controllable interaction
between superconducting qubits and microwave resonators. Up to now, these
transitions have been implemented with voltage drives on the qubit or the
resonator, with the significant disadvantage that such implementations only
lead to second-order sideband transitions. Here we propose an approach to
achieve first-order sideband transitions by relying on controlled oscillations
of the qubit frequency using a flux-bias line. Not only can first-order
transitions be significantly faster, but the same technique can be employed to
implement other tunable qubit-resonator and qubit-qubit interactions. We
discuss in detail how such first-order sideband transitions can be used to
implement a high fidelity controlled-NOT operation between two transmons
coupled to the same resonator.Comment: 15 pages, 5 figure
A new stylolite classification scheme to estimate compaction and local permeability variations
This study was carried out within the framework of DGMK (German Society for Petroleum and Coal Science and Technology) research project 718 “Mineral Vein Dynamics Modeling”, which is funded by the companies ExxonMobil Production Deutschland GmbH, GDF SUEZ E&P Deutschland GmbH, DEA Deutsche Erdoel AG and Wintershall Holding GmbH, within the basic research program of the WEG Wirtschaftsverband Erdoel- und Erdgasgewinnung e.V. We thank the companies for their financial support and their permission to publish these results. This work has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 31688. The Zechstein data were collected with the help of Simon Gast. We thank Jean-Pierre Gratier and an anonymous reviewer for their comments that improved an earlier version of the manuscript.Peer reviewedPostprin
PCA of Fe-oxides MLA data as an advanced tool in provenance discrimination and indicator mineral exploration : case study from bedrock and till from the Kiggavik U deposits area (Nunavut, Canada)
Magnetite and hematite grains from the 0.25–0.5 mm and 0.5–2.0 mm ferromagnetic fractions of ten till samples collected up-ice, overlying and down-ice of the Kiggavik U deposits (Nunavut, Canada), as well as eight bedrock samples from Kiggavik igneous and metasedimentary basement and overlying sedimentary rocks were characterized for their grain size and mineral association using optical microscopy, scanning electron microscopy (SEM) and mineral liberation analysis (MLA). Principal component analysis (PCA) was used to evaluate the MLA data for Fe-oxide mineral association and grain size distribution. PCA shows that mineralogical and granulometric differences in Fe-oxides from Kiggavik igneous rocks distinguish them from that of Kiggavik metasedimentary and sedimentary rocks. In addition, The PCA results indicate that the composition and abundance of minerals associated/intergrown with Fe-oxides are not only different in various till samples, but also in different size fractions of the same sample. Higher proportions of hornblende, quartz, gahnite, grunerite, apatite, chromite and sulfides are intergrown with Fe-oxides in the 0.5–2.0 mm till fraction, as compared to the 0.25–0.5 mm fraction in which Fe-oxides are mostly associated with pyroxene, titanite, rutile, feldspars, calcite and zircon. The mineral associations and grain sizes of proximal bedrocks are reflected in smaller size fractions of Kiggavik till, whereas detrital grains in the 0.5–2.0 mm fraction of Kiggavik till may have originated from distal sources. PCA also shows that Fe-oxides from the Kiggavik bedrock and till can be discriminated from those of volcanogenic massive sulfide (VMS) deposits because of smaller grain sizes and higher abundances of sulfides, gahnite, axinite, corundum, hypersthene and pyroxene intergrown with VMS Fe-oxides. This study emphasizes the importance of selecting suitable representative grain size fractions of till, or other sediments, when using indicator minerals for exploration. The results of PCA of Fe-oxides MLA data are consistent with the results of using Fe-oxides geochemical data in provenance discrimination of Kiggavik till
Assessment of White Spruce and Jack Pine Stem Curvature from a Nelder Spacing Experiment
This study presents a method for calculating stem curvature for trees with multiple deviations. Generally, tree curvature is assessed using the maximum deflection method. It consists of measuring the farthest point from a straight line drawn between the large and small ends of a stem. It works fairly well for a single deviation but gives poorer results for stems with several deviations. The stems used for developing this method were harvested from a 32-yr-old Nelder spacing experiment established near Woodstock, New Brunswick, Canada. A total of 96 trees were selected for this study from the white spruce (Picea glauca [Moench] Voss) and jack pine (Pinus banksiana Lamb.) that were planted on the same Nelder circle. This particular plantation design offered a gradient of initial spacings ranging from 640 to 12,000 stems/ha. Results of analysis revealed that initial spacing had an impact on tree curvature. Stem curvature increased with wider initial spacing. However, this influence varied between species and differed according to the method used to calculate curvature. The vector length calculation method showed that stem curvature in jack pine was more pronounced and more often encountered at lower densities than in white spruce. It was also observed that tree shape was influenced by the cardinal points with white spruce growing more in westerly and southerly directions
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