5,430 research outputs found
A Suite of Spatially Correlated Random Fields of Earthquake Ground Motion in Terms of 1-second Spectral Acceleration Response
No full text
Recent earthquake ground motion prediction equations generally treat the earthquake ground motion field as random, conditioned on a few parameters. These givens mostly include earthquake magnitude, fault rupture mechanism, seismic domain (meaning plate boundary or shield), and spatially varying site conditions such as average shearwave velocity in the upper 30 meters of soil. The ground motion field exhibits spatial correlation: places that are closer together tend to have more similar motion. That spatial correlation can matter to the probability distribution of the aggregate monetary or non-monetary loss experienced by a portfolio of assets, especially if high-value assets can be located within a few kilometers of each other. In a related work (Porter et al. submitted 2023), we estimated the probability distribution of portfolio loss in earthquakes, and therefore wanted to account for the spatial correlation in ground motion. To do so, we generated 100 realizations of a spatially correlated field of standard normal random variates, square, 800 km by 800 km, at 1 km grid spacing each way. Spatial correlation reflects that of 5%-damped, 1-second spectral acceleration response, using the spatial correlation coefficient recommended by Jayaram and Baker (2009). The present work offers those 100 simulated random fields in the form of 100 comma-separated value (CSV) files. See the readme file included with the CSV files for details, including the full bibliographic reference for Jayaram and Baker (2009). Here is the reference for Porter et al. (submitted 2023):Porter, K., Milner, K., and Field, E. (submitted 2023). Trimming the UCERF3-TD logic tree: model order reduction for an earthquake rupture forecast considering loss exceedance. Earthquake Spectra. Submitted Sept. 8, 2023.
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Porter-Blum Ultramicrotome
No full textPorter-Blum ultramicrotome, accession no. 201
Courtesy of the Merrill W. Chase Historic Instrument Collection
Keith Porter designed this ultramicrotome, which was built by instrument maker Josef Blum. Both this instrument and the Claude-Blum ultramicrotome could cut serial sections in ribbons. In 1953 a later version of the Porter Blum instrument, manufactured by Ivan Sorvall, became one of the first commercially available ultramicrotomes. (ca. 1950)
Photo by Lubosh Stepanekhttps://digitalcommons.rockefeller.edu/unseen-world/1022/thumbnail.jp
Keith Porter
No full textPorter sitting on a bench outside.Inscriptions on image and/or album page: "Keith Porter"Digitized by: MBLWHOI Libraryimage/jpg black and white image reformatted digitalPhotograph
KEITH PORTER
No full textKeith Porter, n.d.
Courtesy of the University of Marylandhttps://digitalcommons.rockefeller.edu/tools-for-discovery/1043/thumbnail.jp
Porter, Keith
No full textKeith Porter,1939
Courtesy of the Rockefeller Archive Center
Keith Roberts Porter (1912-1997) was a Canadian-American cell biologist. He studied biology at Acadia University and Harvard University, from which he obtained a Ph.D. in 1938. From 1939 to 1961 he was a member of the Rockefeller Institute in New York City.
In 1970, together with Albert Claude and George E. Palade, Porter was awarded the Louisa Gross Horwitz Prize from Columbia University. Porter\u27s colleagues Albert Claude, Christian de Duve, and George E. Palade were awarded a Nobel Prize in 1974 for describing the structure and function of organelles in biological cells , work that Porter is also well known for.https://digitalcommons.rockefeller.edu/faculty-members/1064/thumbnail.jp
Keith Porter, 1956
No full textKeith R. Porter. The submicroscopic morphology of protoplasm
Lecture delivered March 15, 1956
Posted with permissionhttps://digitalcommons.rockefeller.edu/harvey-lectures/1062/thumbnail.jp
Theoretical frameworks for the learning of geometrical reasoning
No full textWith the growth in interest in geometrical ideas it is important to be clear about the nature of geometrical reasoning and how it develops. This paper provides an overview of three theoretical frameworks for the learning of geometrical reasoning: the van Hiele model of thinking in geometry, Fischbein’s theory of figural concepts, and Duval’s cognitive model of geometrical reasoning. Each of these frameworks provides theoretical resources to support research into the development of geometrical reasoning in students and related aspects of visualisation and construction. This overview concludes that much research about the deep process of the development and the learning of visualisation and reasoning is still needed
Letter from George Palade to Keith Porter
No full textLetter from George Palade to Keith Porter, August 30, 1954https://digitalcommons.rockefeller.edu/unseen-world/1024/thumbnail.jp
Jersey Homesteads -- A Triple Co-operative
No full textChapter 11, pages 256-276, of
Title: "Tomorrow a new world: the New Deal communuity program."
Publisher: Ithaca, NY, Published for the American Historical Association (by) Cornell University Press, 1959.
Author; Conkin, Paul Keith
Keith Porter
No full textKeith Porter, 1939
Courtesy of the Rockefeller Archive Center
Born in 1912 in Yarmouth, Nova Scotia, Porter acquired a love of structure while drawing maps and houses in grade school. He became passionately interested in lichens and small mosses and spent hours studying their shapes on the faces of large Canadian boulders. His first interest in biology came from a high school teacher who allowed a group of boys to do laboratory experiments of their own choosing after school. Following graduation from Acadia University in 1934, with a major in biology and chemistry, he attended Harvard University from which he obtained a Ph.D. in 1938.
Porter attributed his excitement about cells to his Acadia days, when he began to wonder about the exchange between nucleus and cytoplasm: In those days DNA hadn\u27t been discovered and very little was known about the influence of the nucleus on development or any differentiation... I chose to mix different nuclei with the same cytoplasm or different cytoplasms with the same nucleus and they didn\u27t develop the same which means that the cytoplasm was having a rather profound influence on the early morphogenesis of the embryo. - Entering an Unseen World, p. 45https://digitalcommons.rockefeller.edu/unseen-world/1013/thumbnail.jp
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