Search results | Digital Grinnell

Title: A Data Set of Annotated Historical Maps
Description: This data set is designed for testing the performance of optical character recognition (OCR) algorithms on text in scanned historical map images. Thirty maps from the nineteenth and early twentieth centuries (1866–1927) were chosen from nine atlases in the David Rumsey Map Collection. Most maps are of individual states, though some are regional and one is of the entire U.S.; most are manually typeset, with occasional handwritten text. Each place name and many other textual items are annotated with the baseline, bounds, character heights, and ground truth text transcriptions. Several maps also feature USGS GNIS Feature ID tags for labeled items. Java code for processing is provided with the text-based XML annotations, alongside the original, compressed MrSID images and uncompressed TIFF images. We gratefully acknowledge the David Rumsey Map Collection as the source of the map images, which come with the following notice: "Images copyright 2000 by Cartography Associates. Images may be reproduced or transmitted, but not for commercial use. This work is licensed under a Creative Commons [Attribution-NonCommercial-ShareAlike 3.0 Unported] license. By downloading any images from this site, you agree to the terms of that license." The remaining (textual and data) material is hereby licensed CC-BY-NC-SA 4.0 International; the code incorporated is GPL v3.0 (the license is incorporated in the tar file).
PID: grinnell:19349

Title: A New Story : Unifying Derry-Londonderry, Northern Ireland U.K.'s Competing Narratives
Description: Can Derry not only to successfully “rewrite” its past, but redirect its economic and social future?
PID: grinnell:330

Title: Beginner's Field Guide to Grinnell and its Environs
Description: A field guide to the natural environment of the Grinnell area.
PID: grinnell:1676

Title: Deep Neural Networks for Text Detection and Recognition in Historical Maps
Description: Code and experimental data for the ICDAR 2019 paper by Weinman et al. introducing deep convolutional and recurrent neural networks for end-to-end, open-vocabulary text reading on historical maps.
PID: grinnell:23320

Title: Georeferenced Control Points for Historical Maps
Description: This data set consists of nearly 6,400 control points georeferencing 31 historical maps (1831–1927) drawn from the David Rumsey collection. Geographical coordinates use the NAD83 geographical coordinate system. The data is available at https://doi.org/11084/23330.
PID: grinnell:23330

Title: Guide to prairie sites near Grinnell, Iowa
Description: The Center for Prairie Studies at Grinnell College has prepared this brochure to help those wishing to visit prairie sites near Grinnell. The prairie blooms from May to October. Different species flower at different times, so repeat visits during a growing season will be rewarded with an ever-changing palette of colors. No two prairies will have the same mix of species.
PID: grinnell:315

Title: Historical Map Annotations for Text Detection and Recognition
Description: This data is set designed for testing the performance of text/graphics separation and character recognition algorithms on text in scanned historical map images. Thirty one maps from the nineteenth and early twentieth centuries (1866–1927) were chosen from nine atlases in the David Rumsey Map Collection (http://davidrumsey.com). Most maps are of individual U.S. states, though some are regional and one is of the entire U.S.; most feature little handwritten text. The original MrSid files are converted into uncompressed TIFF images for a manual annotation, stored in JSON format. The authors gratefully acknowledge the David Rumsey Map Collection as the source of the map images, which come with the following notice: Images copyright © 2000 by Cartography Associates. Images may be reproduced or transmitted, but not for commercial use. This work is licensed under a Creative Commons [Attribution-NonCommercial-ShareAlike 3.0 Unported] license (http://creativecommons.org/licenses/by-nc-sa/3.0). By downloading any images from this site, you agree to the terms of that license.
PID: grinnell:23294

Title: Ionic Conductivity Studies of LiBOB-doped Silyl Solvent Blend Electrolytes for Lithium-Ion Battery Applications
Description: The ionic conductivity of LiBOB-doped electrolytes containing two silyl solvents, bis[2-(2-methoxyethoxy)ethoxy] dimethylsilane, 1, and [2-(2-methoxyethoxy)ethoxy] trimethylsilane,2, was measured from 10 C to 50 C using AC impedance spectroscopy to assess their potential use in commercial Li-ion cells. The effects of salt concentration, solvent composition, and temperature on the conductivity of the electrolytes are reported. In addition, conductivity data were fit using the Vogel-Tamman-Fulcher (VTF) equation to obtain the parameters s0, T0, and Ea, which correspond closely to conductivity and viscosity. All the electrolytes produced conductivities above the 1.0 mS cm1 threshold required for commercial application. The 1:1 (vl) solvent composition possesses the highest conductivity, with the optimal 0.8 M salt-loading yielding the highest s25 at 1.99 ± 0.02 mS cm1.
PID: grinnell:11474

Title: Jacobian Varieties of Hurwitz Curves with Automorphism Group PSL(2,q)
Description: The size of the automorphism group of a compact Riemann surface of genus g > 1 is bounded by 84(g-1). Curves with automorphism group of size this bound are called Hurwitz curves. In many cases the automorphism group of these curves is the projective special linear group PSL(2,q). We present a decomposition of the Jacobian varieties for all curves of this type and prove that no such Jacobian variety is simple.
PID: grinnell:13254

Title: LaFexCo(1−x)O3 Thin-Film Oxygen Reduction Catalysts Prepared Using Spray Pyrolysis without Conductive Additives
Description: LaFexCo(1−x)O3 thin films were prepared on fluorine-doped tin oxide conducting glass substrates by spray pyrolysis without any conductive additives and evaluated for their ability to catalyze the oxygen reduction reaction. Onset potential and current density were found to be comparable to platinum, and the resulting crystallite size was on the order of 20 nm. Coordination of the precursor metal ions by citrate was found not to be advantageous. Results from multiple scan linear sweep voltammetry suggest lattice oxide saturation during reduction of oxygen and lattice oxide depletion upon water oxidation. The color of the best-performing composition changes dramatically between 1.2 and −1.15 V versus saturated calomel electrode, so X-ray photoelectron spectra of the fully oxidized and reduced films were compared, demonstrating that cobalt in the film changes oxidation state. Performance of the films as a function of iron-to-cobalt ratio is consistent with what others have reported in the literature, indicating that spray pyrolysis is an efficient method to prepare and evaluate new catalytic materials.
PID: grinnell:26882