19468 research outputs found
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Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files
No full textA three-dimensional numerical model of the Amundsen Sea (Antarctica) was used to simulate the period Jan.2006-Mar.2022 under consistent atmospheric/oceanic forcings, bathymetry/ice shelf topography, and model equations/parameters. The model is an implementation of the Regional Ocean Modeling System (ROMS, https://www.myroms.org/) with extensions for sea ice (Budgell 2005) and ice shelves (Dinniman et al. 2011). It simulates the ocean hydrography and circulation, sea ice thermodynamics and dynamics, and the basal melt of the ice shelves, with a uniform horizontal mesh of 1.5km and 20 topography-following vertical levels. Forcings include the ERA5 reanalysis (3-hourly), 10 tidal constituents from CATS 2008, and ocean/sea ice conditions at the edges of the model domain taken from the 5km-resolution circumpolar model of Dinniman et al. 2020 and from daily SSM/I satellite images. The model outputs are divided into nine directories each containing two years worth of model results (run661-669) in the NetCDF format. Each directory contains: daily-averaged model fields (roms_avg_xxxx.nc), instantaneous snapshots every 3 hours for select fields (roms_qck_xxxx.nc), and instantaneous snapshots every 30 days (roms_his_xxxx.nc). All the metadata information necessary for the interpretation of the model outputs (dimensions, units, etc) is included inside the NetCDF files. The NetCDF files follow the CF conventions and can be opened with various software that are open source and freely available over the Internet. In addition to the model outputs, this archive includes the computer code as well as the input files necessary for reproducing the model outputs of this archive.Virginia Institute of Marine Scienc
FDI and Environmental Externalities in Southeast Asia
No full textIn this paper I explore the relationship between foreign direct investment (FDI) and deforestation in Cambodia. Through an event study framework, I show that economic land concessions have a negative relationship with tree cover, over time, having stronger and stronger negative effects. This relationship is more pronounced in foreign economic land concessions when compared to domestic economic land concessions. Through the use of a difference in differences research design I examine the relationship between foreign and domestic concessions through the implementation of a ELC concession ban. The ban only led to worsening levels of deforestation within the borders of foreign economic land concessions. This paper provides evidence that not only is foreign direct investment is a significant driver of deforestation but that also attempts to reduce or stop foreign direct investment can exacerbate levels of deforestation present in a nation already.EconomicsBachelors of Arts (BA
Spatial Variability of Alkali-metal Polarization
No full textAn experiment was conducted at William & Mary to study how alkali polarization varies spatially in a spherical cell during the process of optical pumping. Similar cells are used to study the neutron via electron scattering from polarized 3He nuclei, and those experiments could be improved if alkali polarization is maximized and uniformly distributed throughout the cell. The results of this experiment indicate that the alkali polarization is non-uniform and more heavily concentrated on the side of the cell facing the pump laser.PhysicsBachelors of Science (BS
Fecal Pellet Production by North Atlantic Zooplankton
No full textFecal pellet carbon (FPC) production by zooplankton is a significant component of the ocean’s biological carbon pump: the suite of biological processes that mediate export of carbon to the deep ocean, ultimately leading to the sequestration of atmospheric carbon dioxide in the ocean. In this study, mesozooplankton (zooplankton 0.2 mm to ~2 cm) were collected from the epipelagic zone in the temperate North Atlantic Ocean during day and night in May 2021. Zooplankton were live separated into five size fractions and incubated on board ship in natural surface seawater to measure fecal pellet production rate of the mixed mesozooplankton community. Individual animals in each size class used in experiments were counted and identified by major taxonomic groups, and fecal pellets were counted, measured, and analyzed by CHN analysis to determine amount of particulate organic carbon and nitrogen produced as fecal pellets. Despite having a small contribution to dry-weight biomass relative to individual abundance, zooplankton in the smallest size class (200-500 µm) contributed the most to FPC production. When normalized for total dry weight biomass of animals collected throughout the May 2021 cruise, FPC production was higher during the night than day, but this difference was not significant. This research is important to our understanding of the ocean’s biological pump, allowing us to more accurately model the impact of the open oceans – the largest ecosystem on earth – on long-term climate regulation.BiologyBachelors of Science (BS
Intelligent Software Tooling For Improving Software Development
No full textSoftware has eaten the world with many of the necessities and quality of life services people use requiring software. Therefore, tools that improve the software development experience can have a significant impact on the world such as generating code and test cases, detecting bugs, question and answering, etc. The success of Deep Learning (DL) over the past decade has shown huge advancements in automation across many domains, including Software Development processes. One of the main reasons behind this success is the availability of large datasets such as open-source code available through GitHub or image datasets of mobile Graphical User Interfaces (GUIs) with RICO and ReDRAW to be trained on. Therefore, the central research question my dissertation explores is: In what ways can the software development process be improved through leveraging DL techniques on the vast amounts of unstructured software engineering artifacts? We coin the approaches that leverage DL to automate or augment various software development task as Intelligent Software Tools. To guide our research of these intelligent software tools, we performed a systematic literature review to understand the current landscape of research on applying DL techniques to software tasks and any gaps that exist. From this literature review, we found code generation to be one of the most studied tasks with other tasks and artifacts such as impact analysis or tasks involving images and videos to be understudied. Therefore, we set out to explore the application of DL to these understudied tasks and artifacts as well as the limitations of DL models under the well studied task code completion, a subfield in code generation. Specifically, we developed a tool for automatically detecting duplicate mobile bug reports from user submitted videos. We used the popular Convolutional Neural Network (CNN) to learn important features from a large collection of mobile screenshots. Using this model, we could then compute similarity between a newly submitted bug report and existing ones to produce a ranked list of duplicate candidates that can be reviewed by a developer. Next, we explored impact analysis, a critical software maintenance task that identifies potential adverse effects of a given code change on the larger software system. To this end, we created Athena, a novel approach to impact analysis that integrates knowledge of a software system through its call-graph along with high-level representations of the code inside the system to improve impact analysis performance. Lastly, we explored the task of code completion, which has seen heavy interest from industry and academia. Specifically, we explored various methods that modify the positional encoding scheme of the Transformer architecture for allowing these models to incorporate longer sequences of tokens when predicting completions than seen during their training as this can significantly improve training times.Computer ScienceDoctor of Philosophy (Ph.D.
Characterizing Molecular Environments In Acrylic Paint Via Single-Sided Nmr
No full textAcrylic paint is a modern artistic material made of colored pigment and polymeric binder. Acrylic binder requires fundamental study at the molecular level to understand its physical properties for purposes of art conservation and general polymer chemistry. The research presented in this thesis uses single-sided nuclear magnetic resonance (NMR) as a non-invasive and non-destructive way to measure relaxation and self-diffusion, which provide insight to molecular mobility and physical properties of proton-containing samples. Specifically, this study relies on T2 relaxation to gain insight to regions within acrylic paint with different molecular mobilities. In both dry and wet paint, relaxometry data revealed two relaxation behaviors, each representing a region with unique binder mobility. Furthermore, the effect of pigment concentration on relaxation behavior of wet paint suggested molecules in acrylic binder undergo chemical exchange between these regions with differing mobilities. The characterization of local molecular environments in acrylic paint provides a foundation for future studies of acrylic polymers and contributes fundamental knowledge about the chemistry of acrylic paints to support their long-term preservation.ChemistryMaster of Science (M.Sc.
Dour Hour: The Effects of Policy Uncertainty on Investment Rates in Europe
No full textWhen governments decide to impose policy changes, they cause uncertainty over future policy changes. This uncertainty may, in turn, prevent realization of policy goals. This paper analyzes the effect of policy uncertainty on investment across countries and industries. Specifically, it considers 15 private industry categories (A-N,R in the NACE classification system) across 6 European countries. Results are structured in three parts. The first investigates and compares relationships between Economic Policy Uncertainty (EPU) at the aggregate level across countries. Next, it tries to identify patterns in the Investment Rate responses across industries for each country. Finally, it considers the prevalence of patterns in responses for each industry. The overall pattern seems to be insignificance in the relationship between policy uncertainty and investment rates.. However, for most countries, between one-third to one-half of industries appear to be significantly affected by policy uncertainty. Moreover, both the pattern of results and specific significant industries vary by country.EconomicsBachelors of Arts (BA
Haunted Panes and Psychic Casements: Windows in Wuthering Heights and Villette
No full textthesis examines how windows function in two novels by two sisters—WH by Emily Bronte and Villette by Charlotte Bronte. In both novels windows are metaphorically situated to offer (through expanded vision) the possibility for insight into the psyche or transcendence beyond one current reality into another. Emily and Charlotte’s characters respond to this possibility somewhat differently. Heathcliff and Cathy yearn for the transcendence that windows offer, but in Villette the heroine Lucy Snowe betrays an anxiety about this very phenomenon, seeking to repress her inner world.EnglishBachelors of Arts (BA