1,724,160 research outputs found
Weber, Michael, October 27, 2011 [Interview]
No full textMichael Weber was interviewed on October 27, 2011 by Paul Rule about his childhood, college life at Mount Union College, graduate school at Yale and Boston, and working various jobs. He discussed starting to teaching at Gettysburg part-time while still teaching at Salem State and his impressions of Gettysburg College.Saffel, John; Bowman, William D.Gordon A. Haaland Year
Intercropping Cedrela odorata with Shrubby Crop Species to Reduce Infestation with Hypsipyla grandella and Improve the Quality of Timber
Full text linkCultivation of Cedrela odorata, a valuable tropical hardwood species, is restricted by the mahogany shoot borer (Hypsipyla grandella), whose attacks reduce stem quality in forest plantations. This study investigated whether infestation rates would be reduced and growth performance improved by the intercropping of C. odorata tree seedlings with different crop rotations. The height increment achieved by C. odorata during the first two years was significantly stimulated by the intercropping of maize (Zea mays), pigeon pea (Cajanus cajan), and cassava (Manihot esculenta). Attacks of H. grandella were also considerably reduced in these treatments, compared to the control plots, while intercropping with beans and rice produced no improvement. The effect was particularly distinct when lateral competition between trees and crops was high. Accordingly stem quality was higher in the treatments featuring tall crops. Trees intercropped with C. cajan performed best in terms of height (276 cm ), survival (100% ±0), and quality (81% ±13.5 of trees with satisfying stem quality) after two years. We concluded that intercropping of tree seedlings which are susceptible to H. grandella with shrubby multipurpose species can improve both tree growth and timber quality and hence increase the attractiveness of such species for reforestation
The upper mantle transition zone discontinuities in the Pacific as determined by short-period array data
No full textShort-period array recordings from Pacific earthquakes show precursors to PP produced by underside reflections of P-waves off the discontinuities in the upper mantle. We use these events to study the structure of the transition zone discontinuities in the central and northern Pacific. The discontinuities of the mantle transition zone at depths of 410 km and 660 km are particularly interesting for the interpretation of the chemistry and temperature structure of the mantle transition zone. The PP reflections from these discontinuities are too small to be identified in unprocessed seismograms. Therefore, array methods are used to detect and identify the PP underside reflections. The data of several events show reflections from the 410-km discontinuity. The topography of the reflector can be used to study the olivine to spinel phase transition in the central and northwestern Pacific. The mean depth of the reflector is 404 +/- 16 km with topography near the Hawaiian Islands and the Kuriles. Forward modeling enables an estimate of the minimum impedance contrast and the maximum thickness of the discontinuity. This study shows that the 410-km discontinuity must be sharper than 6 kin, assuming a simple linear gradient for the alpha-->beta phase change, with an impedance contrast of 8.9% as in IASP91, to be in agreement with our data. The minimum impedance contrast for a first-order discontinuity would be 6.5%. The 660-km discontinuity cannot be detected in this dataset using PP underside reflections in agreement with previous studies. Forward modeling shows that the non-detection of the 660 can be explained by a discontinuity with a thickness of more than 12 km for the IASP91 impedance contrast or by a first-order discontinuity with an impedance contrast of less than similar to 9%. (C) 2002 Elsevier Science B.V. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Replication Data for 'Big G'
No full textThe files described below replicate the results of "Big G". They are divided into three parts, which can be found in three different sub-folders: (1) FiveFacts, (2) ModelSimulation, and (3) VAR.
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******************* PART 1: Five Facts on Government spending ***********************
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Folder: FiveFacts
This folder contains code to replicate Figures 1-4 and Tables 1-4 in Section 3 of the paper.
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Data Set-Up
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In order to run the included script files, the main dataset needs to be assembled. The data on federal procurement contracts used in this paper is all publicly available from USASpending.gov. The base dataset used for all of the empirical results in this paper consists of the universe of procurement contract transactions from 2001-2019---around 30 GB of data. Due to its size, the data requires a substantial amount of computing power to work with.
Our approach was to load the data into a SQL database on a server, following the instructions provided by USASpending.gov, which can be found here: https://files.usaspending.gov/database_download/usaspending-db-setup.pdf. As a result, the replication code cannot feasibly start with the raw dataset, though we have provided the raw files at an annual basis at [INSERT URL FOR SITE HERE].
The files "setup_data_1.R", "setup_data_2.R", "setup_data_3.R", and "setup_data_4.R" pull from the SQL database and create intermediate files that are provided with this replication package. You will NOT be able to run the "set_up" files without setting up your own SQL database, but you CAN run the Figure and Table replication code (described below) using the intermediate files created in the setup files.
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Figures
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Figure 1
+ Step 1: Run 'create_contract_proxy.R,' which creates a dataset called 'contracts_for_ramey_merge.dta'
+ Step 2: Run ramey_zubairy_replication.do, which is a file TAKEN DIRECTLY FROM THE REPLICATION PACKAGE
for Ramey & Zubairy (JPE, 2018), found at the link below. We merge our dataset into theirs, and
re-run their regressions on our data.
Ramey & Zubairy (2018) replication: https://econweb.ucsd.edu/~vramey/research/Ramey_Zubairy_replication_codes.zip.
Figure 2
+ 'Figure_2a.R' produces Figure 2a using 'intermediate_file_1.RData'
+ 'Figure_2b.R' produces Figure 2b using 'intermediate_file_2.RData'
Figure 3
+ 'Figure_3a.R' produces Figure 3a using 'intermediate_file_3.RData'
+ 'Figure_3b.R' produces Figure 3b using 'intermediate_file_2.RData'
Figure 4
+ 'Figure_4.R' produces Figures 4a and 4b using 'intermediate_file_3.RData'
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Tables
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Table 1
+ 'Table_1.do' produces Table 1 using 'contracts_for_ramey_merge.dta'
Table 2
+ 'Table_2_upper' produces the top portion of Table 2 using the 'sectors_unbalanced.dta' file created in 'setup_data_4.R'
+ 'Table_2_lower' produces the lower portion of Table 2 using the 'firms_unbalanced.dta' file created in 'setup_data_4.R'
Table 3
+ 'Table_3.R' produces Table 3 using 'intermediate_file_1.RData'.
Table 4
+ Components for Table 4 can be found in 'Figure_3a.R' and 'Figure_3b.R' (noted in those files).
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************************** PART 2: Model Simulation *********************************
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Folder: "ModelSimulation"
+ Matlab file MAIN_generateIRFs.m generates Figures 5 and 6 in the paper. It calls the mod file modelG.mod
+ Matlab file MAIN_generateIRFs_htm.m generates Figure A.21 in the Appendix. It calls the mod file modelG_htm.mod
+ Both files run on Dynare 5.4.
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******************************** PART 3: VAR ****************************************
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Folder: "VAR" (see README in VAR folder for more detail).
Data Setup: "setup_var_data.R," like the files in the FiveFacts folder, will not run. They create a dataset of contracts by month and naics2 sector from the SQL database.
+ 'VAR.do' runs the VAR that produces Figure 7
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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