2,071 research outputs found
Evaluating the SiteStory Transactional Web Archive With the ApacheBench Tool
Conventional Web archives are created by periodically crawling a web site and
archiving the responses from the Web server. Although easy to implement and
common deployed, this form of archiving typically misses updates and may not be
suitable for all preservation scenarios, for example a site that is required
(perhaps for records compliance) to keep a copy of all pages it has served. In
contrast, transactional archives work in conjunction with a Web server to
record all pages that have been served. Los Alamos National Laboratory has
developed SiteSory, an open-source transactional archive written in Java
solution that runs on Apache Web servers, provides a Memento compatible access
interface, and WARC file export features. We used the ApacheBench utility on a
pre-release version of to measure response time and content delivery time in
different environments and on different machines. The performance tests were
designed to determine the feasibility of SiteStory as a production-level
solution for high fidelity automatic Web archiving. We found that SiteStory
does not significantly affect content server performance when it is performing
transactional archiving. Content server performance slows from 0.076 seconds to
0.086 seconds per Web page access when the content server is under load, and
from 0.15 seconds to 0.21 seconds when the resource has many embedded and
changing resources.Comment: 13 pages, Technical Repor
Genetically Modified Crops and Labor Savings in US Crop Production
In spite of widespread adoption there is mixed evidence as to whether or not adopting Genetically Modified (GM) crops increase farm welfare. One possible reason for widespread adoption is labor savings. Using a treatment effect model we estimate the labor savings associated with adopting a GM crop.genetically modified crops, agricultural biotechnology, endogeneity, treatment effects, survey weights, Crop Production/Industries,
Federal Oversight of the Debt Relief Industry: A More Effective Means of Deterring Illegal Debt Settlement Schemes
Total-to-peak ratios of high purity germanium gamma ray detector
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics; and, (S.B.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2004.MIT Institute Archives copy: leaves 2-22 bound in reverse order.Includes bibliographical references (leaf 22).This study is concerned with the percentage of [gamma]-rays of a certain energy having their energy correctly measured by a high purity Germanium [gamma]-ray detector. The ratio between the total counts and the counts within the energy peak (total-to-peak ratio) is determined for seven energies ranging from 89 keV to 1275 keV. A Monte Carlo based on the physical parameters of the detector was used to extrapolate between these points and after an energy independent scaling factor fit the data with a reduced [chi]² slightly below 1. The same experiment was repeated with a lead brick and then a β detector near the Ge detector and these objects were found to not have an effect on the total-to-peak ratios within the precision of the experiment.by Justin Matthew Nelson.S.B
Effective Exchange Rate Classifications and Growth
We propose an econometric procedure for obtaining de facto exchange rate regime classifications which we apply to study the relationship between exchange rate regimes and economic growth. Our classification method models the de jure regimes as outcomes of a multinomial logit choice problem conditional on the volatility of a country's effective exchange rate, a bilateral exchange rate and international reserves. An `effective' de facto exchange rate regime classification is then obtained by assigning country-year observations to the regime with the highest predictive probability obtained from the estimation problem. An econometric investigation into the relationship between exchange rate regimes and GDP growth finds that growth is higher under stable currency-value regimes. Significant asymmetric effects on country growth from not doing what is said are found for nonindustrialized countries. Countries that exhibit `fear of floating' experience significantly higher growth.
Discrimination with a Difference: Can Employment Discrimination Law Accomodate the Americans with Disabilities Act
Genetically Modified Crops, an Input Distance Function Approach
Our initial findings indicate that GM crops do not contribute to the decline of traditional family farms. We make a significant methodological impact by using the within transformation to remove unobserved individual effects and demonstrate that the within transformation results in ML estimates that are identical to OLS estimates.Production Economics, Genetically Modified Crops, Distance Function, Stochastic Frontier Analysis, Production Economics, Research Methods/ Statistical Methods,
Discrimination with a Difference: Can Employment Discrimination Law Accomodate the Americans with Disabilities Act
Shockley-Ramo theorem and long-range photocurrent response in gapless materials
Scanning photocurrent maps of gapless materials, such as graphene, often
exhibit complex patterns of hot spots positioned far from current-collecting
contacts. We develop a general framework that helps to explain the unusual
features of the observed patterns, such as the directional effect and the
global character of photoresponse. We show that such a response is captured by
a simple Shockley-Ramo-type approach. We examine specific examples and show
that the photoresponse patterns can serve as a powerful tool to extract
information about symmetry breaking, inhomogeneity, chirality, and other local
characteristics of the system.Comment: 7 pgs, 3 fg
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