117,638 research outputs found
Algebraic Attacks against Linear RFID Authentication Protocols
No full textThe limited computational resources available on RFID tags imply a
need for specially designed authentication protocols. The light weight
authentication protocol proposed by Juels and Weis seems currently
secure for several RFID applications, but is too slow for many practical
settings.
As a possible alternative, authentication protocols based on choosing
random elements from secret linear -dimensional subspaces of
(so called linear -protocols), have been considered. We show that to a certain extent, these protocols are vulnerable to algebraic
attacks. Particularly, our approach allows to break Cicho'{n}, Klonowski and Kutyl owski's -protocol, a special linear
-protocol, for practically recommended parameters in less
than a second on a standard PC. Moreover, we show that
even unrestricted -protocols can be efficiently broken if is too small
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
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate 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
Fluorescence quenching in β-cyclodextrin vesicles: Membrane confinement and host-guest interactions
No full textFluorescent β-cyclodextrin vesicles (β-CDV) that display host cavities available for host-guest interactions at the vesicle surface were prepared by incorporation of the hydrophobic spirobifluorene-based dye 1 into the membrane of unilamellar vesicles. Fluorescence quenching of dye 1 was observed in the presence of different quenchers. Methyl viologen 2 does not quench dye 1 because it does not bind to β-CDV. 4-Nitrophenol 3 and 4-nitrophenol covalently connected to adamantane 4 quench the fluorescence of dye 1 in neutral solution, but by different mechanisms according to lifetime measurements. The quenching efficiency of 3 is pH dependent due to the presence of the phenolate form. Competition experiments with excess host and guest showed that 3 is likely to diffuse in and out of the membrane, while 4 forms an inclusion complex with β-CDV leading to close contact and efficient quenching. Our findings confirm that this dynamic supramolecular system is a versatile model to investigate quenching and recognition processes in bilayer membranes
Flavonol triglycosides from Ornithopus compressus L. (Fabaceae)
No full textFive flavonoid glycosides were isolated from the aerial parts of Ornithopus compressus L., yellow serradella (Fabaceae). The structures of the isolated natural products were determined as kaempferol 3-O-(2,6-di-O-β-D-glucopyranosyl)-β-D-galactopyranoside (1), kaempferol 3-O-β-D-glucopyranosyl-(1→6)-[2-O-(2E)-feruloyl-β-glucopyranosyl]-(1→2)-β-D-galactopyranoside (2), quercetin 3-O-(2,6-di-O-β-D-glucopyranosyl)-β-D-galactopyranoside (3), quercetin 3-O-β-D-glucopyranosyl-(1→6)-[2-O-(2E)-feruloyl-β-glucopyranosyl]-(1→2)-β-D-galactopyranoside (4), and isorhamnetin 3-O-(2,6-di-O-β-D-glucopyranosyl)-β-D-galactopyranoside (5). While compounds 1 and 3 have been described previously, compounds 2, 4 and 5 represent formerly undescribed natural products. For structure elucidation UV, HRMS, and NMR (1H NMR, 13C NMR, H,H-COSY, HMBC, and HSQC) were employed. Absolute sugar configurations were confirmed using GLC–MS/MS after hydrolysis, octylation, and acetylation of the isolated compounds. Additionally, DPPH radical and ABTS radical cation scavenging activities as well as cytotoxic activities of the isolated compounds were assessed
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Sarah L. Blum Author Visit - Warrior Nurse: PTSD and Healing
No full textHear Sarah L. Blum, author of Women Under Fire: Abuse in the Military, discuss her newest book, Warrior Nurse: PTSD and Healing followed by a Q&A and book signing.
Sarah L. Blum is a decorated Vietnam veteran who served as an operating room nurse during the intense fighting of 1967. In recognition of her service, she was awarded the Army Commendation Medal.
Sponsored by CWU Veterans Center and CWU Libraries.https://digitalcommons.cwu.edu/libraryevents/1252/thumbnail.jp
Lillian L. Lambert, Author, Speaker, and Entrepreneur
No full textLillian L. Lambert, Author, Speaker, and Entrepreneu
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