1,761,766 research outputs found
A g-factor metric for k-t SENSE and k-t PCA based parallel imaging
No full textPURPOSE: To propose and validate a g-factor formalism for k-t SENSE, k-t PCA and related k-t methods for assessing SNR and temporal fidelity.
METHODS: An analytical gxf -factor formulation in the spatiotemporal frequency domain is derived, enabling assessment of noise and depiction fidelity in both the spatial and frequency domain. Using pseudoreplica analysis of cardiac cine data the gxf -factor description is validated and example data are used to analyze the performance of k-t methods for various parameter settings.
RESULTS: Analytical gxf -factor maps were found to agree well with pseudoreplica analysis for 3x, 5x, and 7x k-t SENSE and k-t PCA. While k-t SENSE resulted in lower average gxf values (gx (avg) ) in static regions when compared with k-t PCA, k-t PCA yielded lower gx (avg) values in dynamic regions. Temporal transfer was better preserved with k-t PCA for increasing undersampling factors.
CONCLUSION: The proposed gxf -factor and temporal transfer formalism allows assessing noise performance and temporal depiction fidelity of k-t methods including k-t SENSE and k-t PCA. The framework enables quantitative comparison of different k-t methods relative to frame-by-frame parallel imaging reconstruction. Magn Reson Med 75:562-571, 2016. © 2015 Wiley Periodicals, Inc
Telegram from K. T. Keller to Minnie Meacham Carter
Full text linkTelegram from K. T. Keller to Minnie Meacham Carter upon the death of Amon Giles Carter. The telegram expresses condolences about his death.https://mavmatrix.uta.edu/specialcollections_meachamcarterpapers/1444/thumbnail.jp
The K-T Extinction
No full textThis chapter from the book History of Life describes the results of the K-T extinction and looks at the Impact theory and a giant volcanic eruption as possible causes. The essay covers the catastrophic scenarios for extinction that could result from these events. After reviewing the paleontological record across the K-T boundary, the author concludes that it is not clear that the catastrophes themselves can explain the extinction patterns that we see in the fossil record. Educational levels: Graduate or professional, Undergraduate lower division, Undergraduate upper division
Postcard from K. T. Reddell to Oscar Monnig (October 11, 1946)
No full textPostcard from K. T. Reddell to Oscar Monnig thanking him for the check as it was more than he expected. States that he would be most happy to locate the spot that the Gail Borden meteorite was found as closely as he can.Oct. 11, 1946. Dear Sir, Thanks for the check - it was more than I expected. I'll be glad to locate the spot as nearly as I can on the map. Yours truly, K. T. Reddell, O'Donnell, Tex
Informational Postcard on the Gail Borden Meteorite Filled Out by K. T. Reddell (September 30, 1946)
No full textInformational Postcard filled out by K. T. Reddell and sent to Oscar Monnig answering questions relating to the Gail Borden Meteorit
Informational Postcard on the Gail Borden Meteorite Filled Out by K. T. Reddell (October 11, 1946)
No full textInformational Postcard filled out by K. T. Reddell and sent to Oscar Monnig answering questions relating to the finding of the Gail Borden Meteorit
Postcard from Oscar Monnig to K. T. Reddell with Response (October 23, 1946)
No full textPostcard from Oscar Monnig to K. T. Reddell with a typed set of questions relating to how Reddell came into possession of the Gail Borden meteorite. Features handwritten response from Reddell to Monnig.I don't know how the stone got there. It was plain it had been there for some time. I gave the check to Mr. Smith - he was perfectly satisfied with the sale. Yours truly, K. T. Reddel
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
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