177,460 research outputs found
Incidents of the war. Marshall house, Alexandria, Va. August, 1862.
No full textIncidents of the War. Marshall House, Alexandria, VA. August, 1862.Exterior view of Marshall House and adjoining buildings.Title from piece.Printed on recto: Negative by Wm. R. Pywell. Entered according to act of Congress in the year 1865, by A. Gardner, in the Clerk's Office of the District Court of the District of Columbia. Positive by A. Gardner, 511 7th St., Washington. Published by Philp & Solomons, Washington
Incidents of the war. Slave pen, Alexandria, Va. August, 1863.
No full textIncidents of the War. Slave Pen, Alexandria, VA. August, 1863.Photograph shows exterior view of buildings along 1300 Block, Duke Street, including Price, Birch & Co., which were used to hold slaves awaiting auction.Title from piece.Printed on recto: Negative by Wm. R. Pywell. Entered according to act of Congress in the year 1865, by A. Gardner, in the Clerk's Office of the District Court of the District of Columbia. Positive by A. Gardner, 511 7th St., Washington. Published by Philp & Solomons, Washington
Incidents of the war. Old capitol prison, Washington.
No full textIncidents of the War. Old Capitol Prison, Washington.The prison located behind the Capitol building in which a number of Confederate prisoners were held.Title from piece.Printed on recto: Negative by Wm. R. Pywell. Entered according to act of Congress in the year 1865, by A. Gardner, in the Clerk's Office of the District Court of the District of Columbia. Positive by A. Gardner, 511 7th St., Washington. Published by Philp & Solomons, Washington
Proceedings of the international workshop on multi-micronutrient deficienty control in the life cycle
No full textAppropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Bounce conditions in f(R) cosmologies
No full textWe investigate the conditions for a bounce to occur in Friedmann-Robertson-Walker cosmologies for the class of fourth-order gravity theories. The general bounce criterion is determined and constraints on the parameters of three specific models are given in order to obtain bounce solutions. Furthermore, unlike the case of general relativity, a bounce appears to be possible in open and flat cosmologies. © 2006 IOP Publishing Ltd
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Approach to headaches in children
No full textCITATION: Solomons, R., Schoeman, J. & Van Toorn, R. 2011. Approach to headaches in children. Continuing Medical Education, 29(4):171-174.The original publication is available at http://www.cmej.org.zaHeadache is a common problem in childhood
– up to 25% of schoolchildren suffer from
chronic, recurrent headaches. Although
primary headaches are far more common
than those with a secondary cause, it is the
latter that result in the most anxiety for
families.1 A logical approach to investigating
and managing headaches is needed.http://www.cmej.org.za/index.php/cmej/article/view/2162Publisher's versio
Structure formation in modified gravity
No full textWe pursue a (l+3)-covariant analysis of cosmological peculiar velocity of pressure-free matter induced by the matter density perturbations in modified f(R) gravity theories. Instead of working in a quasi-Newtonian Eulerian frame, we select a curvature comoving Lagrangian frame, which means the shear and heat energy flux are non-zero. This is part of ongoing work on the end-structure of a generic over-density in f(R) gravity. © 2009 American Institute of Physics
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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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