Search Constraints
Number of results to display per page
View results as:
Search Results
-
- Creator:
- Tye, Alexander R, Wolf, Aaron S, and Niemi, Nathan A
- Description:
- Detrital zircon age distributions provide robust insights into past sedimentary systems, but these age distributions are often complex and multi-peaked, with sample sizes too small to confidently resolve population distributions. This limited sampling hinders existing quantitative methods for comparing detrital zircon age distributions, which show systematic dependence on the sizes of compared samples. The proliferation of detrital zircon studies motivates the development of more robust quantitative methods. We present the first attempt, to our knowledge, to infer probability model ensembles (PMEs) for samples of detrital zircon ages using a Bayesian method. Our method infers the parent population age distribution from which a sample is drawn, using a Monte Carlo approach to aggregate a representative set of probability models that is consistent with the constraints that the sample data provide. Using the PMEs inferred from sample data, we develop a new estimate of correspondence between detrital zircon populations called Bayesian Population Correlation (BPC). Tests of BPC on synthetic and real detrital zircon age data show that it is nearly independent from sample size bias, unlike existing correspondence metrics. Robust BPC uncertainties can be readily estimated, enhancing interpretive value. When comparing two partially overlapping zircon age populations where the shared proportion of each population is independently varied, BPC results conform almost perfectly to expected values derived analytically from probability theory. This conformity of experimental and analytical results permits direct inference of the shared proportions of two detrital zircon age populations from BPC. We provide MATLAB scripts to facilitate the procedures we describe.
- Keyword:
- provenance, statistics, zircon, Bayesian, detrital, and density estimation
- Citation to related publication:
- A.R. Tye, A.S. Wolf, N.A. Niemi, Bayesian population correlation: A probabilistic approach to inferring and comparing population distributions for detrital zircon ages, Chemical Geology, Volume 518, 2019, Pages 67-78, ISSN 0009-2541, https://doi.org/10.1016/j.chemgeo.2019.03.039
- Discipline:
- Science
-
- Creator:
- Ozturk, Dogacan
- Description:
- The global magnetosphere-ionosphere-thermosphere (M-I-T) system is intrinsically coupled and susceptible to external drivers such as solar wind dynamic pressure enhancements. In order to understand the large-scale dynamic processes in the M-I-T system due to the compression from the solar wind, the 17 March 2015 sudden commencement was studied in detail using global numerical models. This data set is comprised of the simulation data generated from these models. and NOTE: The following changes were made to this dataset on March 28, 2018. First, two mp4 files were added. Second, the symbol representing "degree" was not rendering properly in the README file. The symbols were removed and replaced with the word "degree". Third, the metadata in the "methodology" and "description" fields were revised for content and clarity. On April 16, 2018 a citation to the corresponding article was added to the metadata record.
- Keyword:
- MHD model, BATS'R'US, and GITM
- Citation to related publication:
- Ozturk, D. S., Zou, S., Ridley, A. J., & Slavin, J. A. (2018). Modeling study of the geospace system response to the solar wind dynamic pressure enhancement on 17 March 2015. Journal of Geophysical Research: Space Physics, 123, 2974–2989. https://doi.org/10.1002/2017JA025099
- Discipline:
- Science
-
- Creator:
- Johnson, Jena E.
- Description:
- Note: The "Readme_Metadata" file was updated on March 15, 2018 to include a citation to the related article making use of this data and was reformatted to be presented as a pdf file rather than as a docx file. and This data set is comprised of synchrotron-based X-ray transmission and absorption spectroscopy data as well as X-ray diffraction patterns that were performed to characterize the best-preserved examples of nanoscale iron silicate mineral inclusions from 2.5 billion-year-old Banded Iron Formations (BIFs) and ferruginous cherts.
- Keyword:
- Precambrian banded iron formations and nanoparticle inclusions of iron silicates in chert
- Citation to related publication:
- Johnson, J. E., Muhling, J. R., Cosmidis, J., Rasmussen, B. & Templeton, A. S. (2018). Low-Fe(III) Greenalite Was a Primary Mineral from Neoarchean Oceans. Geophysical Research Letters, 45. https://doi.org/10.1002/2017GL076311
- Discipline:
- Science
-
- Creator:
- Sick, Volker , Reuss, David L, and Greene, Mark L
- Description:
- This archive contains data files from spark-ignited homogeneous combustion internal combustion engine experiments. Included are high-resolution two-dimensional two-component velocity fields acquired at two 5 x 6 mm regions, one near the head and one near the piston. Crank angle resolved heat flux measurements were made at a third location in the head. The engine was operated at 40 kPa, 500 and 1300 RPM, motor and fired. Included are in-cylinder pressure measurements, external pressure and temperature data, as well as details on the geometry of the optical engine to enable setups of simulation configurations.
- Keyword:
- combustion, internal combustion engine, heat Transfer, particle image velocimetry, in-cylinder flow, TCC III engine , optical engine, CFD validation, PIV, boundary layer, and turbulence
- Discipline:
- Engineering
-
- Creator:
- Flanner, Mark
- Description:
- Greenhouse gas (GHG) additions to Earth’s atmosphere initially reduce global outgoing longwave radiation (OLR), thereby warming the planet. In select environments with temperature inversions, however, increased GHG concentrations can actually increase local OLR. Negative top-of-atmosphere and effective radiative forcing (ERF) from this situation give the impression that local surface temperatures could cool in response to GHG increases. Here we consider an extreme scenario in which GHG concentrations are increased only within the warmest layers of winter near-surface inversions of the Arctic and Antarctic. We find, using a fully coupled Earth system model, that the underlying surface warms despite the GHG addition exerting negative ERF and cooling the troposphere in the vicinity of the GHG increase. This unique radiative forcing and thermal response is facilitated by the high stability of the polar winter atmosphere, which inhibits thermal mixing and amplifies the impact of surface radiative forcing on surface temperature. These findings also suggest that strategies to exploit negative ERF via injections of short-lived GHGs into inversion layers would likely be unsuccessful in cooling the planetary surface. and Note: A revised data description file was added to this work on April 11, 2018 containing additional information about the data set than was provided in the original description. Additional keywords and a full citation to the related article were added as well.
- Keyword:
- climate, greenhouse gas, polar inversion layers, radiative forcing (and/or effective radiative forcing), and MODTRAN simulation
- Citation to related publication:
- Flanner, M. G., Huang, X., Chen, X.,& Krinner, G. (2018). Climate response to negative greenhouse gas radiative forcing in polar winter. Geophysical Research Letters, 45, 1997–2004. https://doi.org/10.1002/2017GL076668
- Discipline:
- Science
-
- Creator:
- de Oliveira, Stephanie and Nisbett, Richard E.
- Description:
- These studies assess the effect of social identity on judgement and are described in "Demographically diverse crowds are typically not much wiser than homogeneous crowds" (de Oliveira, S., & Nisbett, R. E. Proceedings of the National Academy of Sciences, 2018) and the article’s Supporting Information appendix. Some studies use a variety of questions to assess multiple social identity factors; the other studies are narrowed to particular social identity variables. Each study includes some type of estimation or prediction task, collects social identity variables, and asks participants to indicate their answer strategies. Study 1 is a trivia and prediction task based on football team fan identity. Study 2 reports on demographics plus political and religious identity and asks participants to predict vote percentages in presidential primaries. Study 3 participants estimate the percentage of Americans that support statements on various polarizing political views and give likelihood ratings for presidential candidates to win the Iowa caucus; a variety of identity questions are asked including political and religious identity. Study 4 includes demographics plus political and religious identity questions and asks participants to predict how the candidates would perform in the 2016 United States presidential election. Study 5 asks participants to guess the popularity rating of books that had either gender-specific or gender-neutral appeal, and also to rate their own interest in the books. Demographic-based social identity variables such as sex are included. Study 6 includes a wide variety of social identity variables and asks participants to estimate the likelihood of events occurring in the near future. Study 7 participants are from diverse national backgrounds and completed judgement tasks that predicted stock prices, Olympic performance, and news events outcomes. The data are generally interpretable when examined in conjunction with the target article. A new data file for Study 6 was uploaded on April 4, 2018 to include variables that were inadvertently left out of the original Study 6 file. A new data file for Study 7 was uploaded on April 6, 2018 to include variables that were inadvertently left out of the original Study 7 file. A codebook for this data set was added on April 6, 2018.
- Keyword:
- Judgment/Decision Making and Estimate aggregation
- Citation to related publication:
- Demographically diverse crowds are typically not much wiser than homogeneous crowds. Stephanie de Oliveira Richard E Nisbett Proceedings of the National Academy of Sciences of the United States of America vol. 115 issue 9 (2018) pp: 2066-2071. https://doi.org/10.1073/pnas.1717632115
- Discipline:
- Social Sciences
-
- Creator:
- Geng, Yina, Van Anders, Greg, and Glotzer, Sharon C.
- Description:
- The data are the 13 target structures used in developing our model for predicting colloidal crystal structures from the geometries of particular shapes. The target structures are: simple cubic (SC), body-centered cubic (BCC), face-centered cubic (FCC), simple chiral cubic (SCC), hexagonal (HEX-1-0.6), diamond (D), graphite (G), honeycomb (H), body-centered tetragonal (BCT-1-1-2.4), high-pressure Lithium (Li), Manganese (beta-Mn), Uranium (beta-U), Tungsten (beta-W). At least nine simulations were run on each of the target structures. All of the data are formatted as .pos files.
- Keyword:
- Inverse Design and Machine Learning
- Citation to related publication:
- " Yina Geng, Greg van Anders, Sharon C. Glotzer, ""Predicting colloidal crystals from shapes via inverse design and machine learning [pre-print]"" https://arxiv.org/pdf/1801.06219.pdf"
- Discipline:
- Science
-
- Creator:
- Fries, Kevin J
- Description:
- This data is in support of the publication in review "Using sensor data to dynamically map large-scale models to site-scale forecasts: A case study using the National Water Model". It is all the raw data extracted from the NWM flow forecasts for Iowa and the IFIS stage readings. For the NWM data, each date has it's own tab-delimited file with columns being the time (hrs) and rows being the NHD site. For the IFIS gages, each tab delimited file is for a single site for the period of record.
- Keyword:
- student-friendly
- Citation to related publication:
- Fries, K. J., & Kerkez, B. (2018). Using sensor data to dynamically map large-scale models to site-scale forecasts: A case study using the national water model. Water Resources Research, 54, 5636-5653. https://doi.org/10.1029/2017WR022498
- Discipline:
- Engineering
-
- Creator:
- Gosner, Linda R. and Smith, Alexander J.
- Description:
- Included here are 1) a detailed description of each of the dataset's components, 2) a database of all finds from the 2015 survey, 3) a database of faunal bone compiled by specialist Damià Ramis, 4) a description of the finds by category to accompany these databases, 5) a PDF of notes taken in the field, 6) field photographs of survey units, 7) object photographs of all finds, and 8) drawings of diagnostic ceramics by time period.
- Keyword:
- Sardinia, Mediterranean archaeology, archaeological survey, pedestrian survey, and Classical archaeology
- Citation to related publication:
- Stiglitz, Alfonso, Enrique Díes Cusí, Damià Ramis, Andrea Roppa, and Peter van Dommelen. “Intorno Al Nuraghe: Notizie Preliminari Sul Progetto S’Urachi (San Vero Milis, OR).” Quaderni. Rivista Di Archeologia 26 (2015): 191–218. https://quaderniarcheocaor.beniculturali.it/index.php/qua/article/view/80/78
- Discipline:
- Social Sciences
-
- Creator:
- Mathews, Elizabeth and Verhoff, Frank
- Description:
- Each pdf is an electronic version of the paper output for each experiment. Each text file is the electronic version of the data on the computer cards for each experiment. These text files are directly readable by Excel. Once in Excel, the data can be manipulated as desired. Additional information is in the theses.
- Keyword:
- Two Liquid Phase Processes, Droplet Size and Concentration, Population Balances, and Dispersed Phase Mixing
- Citation to related publication:
- Ross, S. L. (1971). Measurements and models of the dispersed phase mixing process (Doctoral dissertation). Retrieved from http://hdl.handle.net/2027.42/136886 and Verhoff, F. H. (1969). A study of the bivariate analysis of dispersed phase mixing (Doctoral dissertation). Retrieved from http://hdl.handle.net/2027.42/137651
- Discipline:
- Science and Engineering