3,251 research outputs found
trackr: A Framework for Enhancing Discoverability and Reproducibility of Data Visualizations and Other Artifacts in R
Research is an incremental, iterative process, with new results relying and
building upon previous ones. Scientists need to find, retrieve, understand, and
verify results in order to confidently extend them, even when the results are
their own. We present the trackr framework for organizing, automatically
annotating, discovering, and retrieving results. We identify sources of
automatically extractable metadata for computational results, and we define an
extensible system for organizing, annotating, and searching for results based
on these and other metadata. We present an open-source implementation of these
concepts for plots, computational artifacts, and woven dynamic reports
generated in the R statistical computing language
rtables -- A Framework For Creating Complex Structured Reporting Tables Via Multi-Level Faceted Computations
Tables form a central component in both exploratory data analysis and formal
reporting procedures across many industries. These tables are often complex in
their conceptual structure and in the computations that generate their
individual cell values. We introduce both a conceptual framework and a
reference implementation for declaring, generating, rendering and modeling such
tables. We place tables within the existing grammar of graphics paradigm for
general statistical visualizations. Our open source `rtables` software
implementation utilizes these connections to facilitate an intuitive way to
declare complex table structure and construct those tables from data. In the
course of this work, we relax several constraints present in the traditional
grammar of graphics framing. Finally, `rtables` models instantiated tables as
tree structures, which allows powerful, semantically meaningful and
self-describing queries and manipulations of tables after creation. We showcase
our framework in practice by creating complex, realistic example tables.Comment: Submitted for publication to the Journal of Computational and
Graphical Statistic
Drivers of Demand for Imported Horticultural Commodities: A Cross-Country Comparison
International trade of horticultural commodities is increasingly important in many regions of the world, yet relatively little research has studied import patterns of key horticultural crops. Using data between 1991 and 2005, we find that import demand for horticultural commodities in developed countries has been driven primarily by prices and the level of trade openness while income and diet considerations were more important in emerging countries. Furthermore, our results show that the determinants of import demand differed across the selected crops, and therefore information can be lost if data for horticultural commodities are aggregated.Emerging markets, Horticultural commodities, Import demand, International trade, International Relations/Trade, Marketing, Q10, Q13, Q17,
Import Demand for Horticultural Commodities in Developed and Emerging Countries
International trade of horticultural commodities is increasingly important in many regions of the world, yet import patterns of key horticultural crops are understudied in the agricultural economics literature. Using data between 1991 and 2005, we estimate the drivers of per capita import demand for six of the most highly traded horticultural commodities. The own price elasticity estimates were negative in all import demand models and, in most cases, the effects were statistically stronger for importers in emerging countries. Import demand for horticultural commodities in developed countries has been driven primarily by prices and the level of trade openness while income and diet considerations were more important in emerging countries. Furthermore, our results show that the determinants of import demand differed across the six models, and therefore, information can be lost when data for horticultural commodities are aggregated.Emerging markets, Horticultural commodities, Import demand, International trade, Agricultural and Food Policy, International Relations/Trade, Q17,
Pulsations in M dwarf stars
We present the results of the first theoretical non-radial non-adiabatic
pulsational study of M dwarf stellar models with masses in the range 0.1 to
0.5M_solar. We find the fundamental radial mode to be unstable due to an
\epsilon mechanism caused by deuterium (D-) burning for the young 0.1 and
0.2M_solar models, by non-equilibrium He^3 burning for the 0.2 and 0.25M_solar
models of 10^4Myr, and by a flux blocking mechanism for the partially
convective 0.4 and 0.5M_solar models once they reach the age of 500Myr. The
periods of the overstable modes excited by the D-burning are in the range 4.2
to 5.2h for the 0.1M_solar models and is of order 8.4h for the 0.2M_solar
models. The periods of the modes excited by He^3 burning and flux blocking are
in the range 23 to 40min. The more massive and oldest models are more promising
for the observational detection of pulsations, as their ratio of instability
e-folding time to age is more favourable.Comment: 5 pages, 4 figures, 2 tables. Accepted for publication in MNRAS
Letters on 2011 October 11 Version 2 is the accepted manuscript with changes
in boldfac
Resistance of the Freshwater Microbiome to a Combination of Pesticides
Undergraduate
Basi
The dispersion curve applied in guided wave propagation in prismatic rods
The early detection of failures in structures is a subject of great interest in engineering; several of these techniques are linked with the elastic wave propagation, using guided waves is one of these alternatives. Several structures of interest in engineering are laminar arrangements; the wave propagation in this type of structures depends not only on the material properties, but also on the geometric parameters, such as the plate thickness. Tubular structures, pressure vessels, tanks and also parts of ships hulls could be considered laminar. The elastic wave propagation in laminar structures could be considered as a sum of modal shapes that have its wave length and frequencies defined. These mode families are characteristics of each structure and could be represented through the dispersion curves. The definition of these dispersion curves is of crucial importance to understand the propagation of guided waves in the structure studied. In the present work the dispersion curves were generated using three different methodologies, specific for metallic rectangular stems that compound the strengthening armor in flexible riser duct. Each approach presented in the analysis were carried out using standard finite element commercial packages and an experimental verification, as well. The premise is to present the topics in the simplest way, not only to understand how the dispersion curves are built but also how these curves must be interpreted
A Survey of Large Language Models in Cybersecurity
Large Language Models (LLMs) have quickly risen to prominence due to their
ability to perform at or close to the state-of-the-art in a variety of fields
while handling natural language. An important field of research is the
application of such models at the cybersecurity context. This survey aims to
identify where in the field of cybersecurity LLMs have already been applied,
the ways in which they are being used and their limitations in the field.
Finally, suggestions are made on how to improve such limitations and what can
be expected from these systems once these limitations are overcome
Import Demand for Horticultural Commodities in Developed and Emerging Countries
WP 2008-24 December 2008JEL Classification Codes: Q17International trade of horticultural commodities is increasingly important in many regions of the world, yet import patterns of key horticultural crops are understudied in the agricultural economics literature. Using data between 1991 and 2005, we estimate the drivers of per capita import demand for six of the most highly traded horticultural commodities. The own price elasticity estimates were negative in all import demand models and, in most cases, the effects were statistically stronger for importers in emerging countries. Import demand for horticultural commodities in developed countries has been driven primarily by prices and the level of trade openness while income and diet considerations were more important in emerging countries. Furthermore, our results show that the determinants of import demand differed across the six models, and therefore, information can be lost when data for horticultural commodities are aggregated
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