117,948 research outputs found
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
[Epreuve d'imprimeur] / Guides Joanne
No full textÉchelle(s) : [Echelles diverses]Comprend : Savoie / Grave A. Rabin ; Fontainebleau / R. Bolzé, Del. ; Bois de Boulogne / L. Thuillier, Del.t ; Pau ; Arcachon / d'après le plan dressé par M. Pascaud Agent-Voyer ; Lyon (centre de la ville) ; Clermont-Ferran
Evaluation of microplasma discharges as active components for reconfigurable antennas
No full textThis paper presents an experimental setup for the wideband RF characterization of plasma Micro Hollow Cathode Sustained Discharge (MHCD). This microdischarge is studied as a candidate for integrated active component in antennas, using the change of permittivity caused by the presence of plasma. The measurement setup consists of a 50 Ω microstrip line with a single MHCD placed in its center. The measurement of the scattering parameters of the experimental device permits the evaluation of the complex permittivity and conductivity of the MHCD
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
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
Plasma-based electrically small antenna
No full textGaz ionisés composés d’électrons, d’ions et de neutres, les décharges plasmas ont déjà démontré leur potentialité pour le développement de systèmes radiofréquences et micro-ondes. Plus particulièrement, le contrôle de la densité électronique et l’aspect allumage/extinction (mode ON/OFF) des décharges plasmas suscitent un intérêt croissant pour le développement d’antennes furtives reconfigurables en fréquence et/ou en diagramme de rayonnement. Ces antennes exploitent principalement deux comportements électromagnétiques des décharges plasmas, le comportement électrique, pour lequel la partie réelle de la permittivité relative du plasma est grandement négative, et le comportement diélectrique lorsque cette dernière est comprise entre 0 et 1.Récemment, un nouveau type d’antenne plasma miniature a été proposé et expérimentalement étudié en bande VHF [1]. Dans son utilisation, le plasma ne se comporte ni comme un bon conducteur électrique, ni comme un matériau diélectrique, mais comme un mauvais conducteur aussi appelé matériau ENG (Epsilon NéGatif). L’antenne consiste alors en un monopole miniature couplé à un résonateur ENG hémisphérique de dimension sub-longueur d’onde obtenu grâce à une décharge plasma. Les travaux présentés dans [1], issus d’une précédente thèse [2], permirent de mettre en évidence un phénomène de résonance associé à un rayonnement électromagnétique de l’antenne plasma miniature. La reconfigurabilité en fréquence de l’antenne a également été observée en modifiant la puissance électromagnétique communiquée au plasma et donc sa densité électronique.Dans ces travaux de thèse, nous poursuivons le développement de cette antenne plasma miniature. Plus spécifiquement, ce travail de recherche a pour but de :• comprendre le phénomène physique opérant au sein du plasma à l’origine du rayonnement électromagnétique de l’antenne plasma miniature,• mettre en œuvre des dispositifs de mesure pour évaluer ses performances antennaires,• étudier expérimentalement les propriétés potentielles de durcissement électromagnétique de l’antenne,• proposer une modélisation numérique de cette antenne non-standard.Au cours de cette thèse, les différents travaux de recherche ayant été menés afin de répondre aux objectifs sont :• un état de l’art sur les antennes à plasma,• le développement d’un modèle analytique afin de proposer une description phénoménologique de la résonance plasmonique, phénomène physique à l’origine du rayonnement électromagnétique de l’antenne,• l’élaboration de dispositifs de mesure dédiés à la caractérisation des propriétés de cette antenne,• la mesure des performances de l’antenne plasma miniature ainsi que la mise en évidence expérimentale de ses propriétés de durcissement électromagnétique.• la mise en œuvre d’une stratégie pour modéliser numériquement cette antenne plasma miniature.[1] V. Laquerbe, R. Pascaud, A. Laffont, T. Callegari, L. Liard and O. Pascal, "Towards antenna miniaturization at radio frequencies using plasma discharges," Phys. Plasmas, vol. 26, no. 3, p. 033509, 2019[2] V. Laquerbe, Etude théorique et expérimentale d’un nouveau concept d’antenne VHF miniature et accordable par décharge plasma. PhD thesis, ISAE-Supaéro, 2017Ionized gas composed of electrons, ions and neutrals, plasma discharges have already demonstrated their potential for the development of radio frequency and microwave systems. In particular, the control of the electron density and the ON/OFF aspect of plasma discharges are of growing interest for the development of stealth antennas reconfigurable in frequency and/or in radiation pattern. These antennas mainly exploit two electromagnetic behaviors of plasma discharges, the electrical behavior, for which the real part of the relative permittivity of the plasma is largely negative, and the dielectric behavior when the latter is between 0 and 1.Recently, a new type of electrically small plasma-based has been proposed and experimentally studied in VHF band [1]. In this case, plasma behaves neither as a good electrical conductor, nor as a dielectric material, but as a bad conductor also called ENG (Epsilon NeGative) material. The antenna then consists of a small monopole coupled to a sub-wavelength hemispherical ENG resonator obtained with a plasma discharge. The work presented in [1], resulting from a previous thesis [2], allowed to highlight a resonance phenomenon associated with an electromagnetic radiation of the electrically small plasma-based antenna. The frequency reconfigurability of the antenna was also observed by modifying the electromagnetic power communicated to the plasma, that is to say its electron density.In this work, we continue the development of this electrically small plasma-based antenna. More specifically, this research work aims to :- understand the physical phenomenon operating within the plasma at the origin of the electromagnetic radiation of the electrically small plasma-based antenna,- implement measurement devices to evaluate its antenna performances,- experimentally study the potential electromagnetic hardening properties of the antenna,- propose a numerical model of this non-standard antenna.During this thesis, the different research works that have been carried out to meet the objectives are :- a state of the art on plasma-based antennas,- the development of an analytical model in order to propose a phenomenological description of the plasmonic resonance, physical phenomenon at the origin of the electromagnetic radiation of the antenna,- the development of measurement devices dedicated to the characterization of the properties of this antenna,- the measurement of the performances of the electrically small plasma-based antenna as well as the experimental demonstration of its electromagnetic hardening properties.- the implementation of a strategy to numerically model this antenna.[1] V. Laquerbe, R. Pascaud, A. Laffont, T. Callegari, L. Liard and O. Pascal, "Towards antenna miniaturization at radio frequencies using plasma discharges," Phys. Plasmas, vol. 26, no. 3, p. 033509, 2019[2] V. Laquerbe, Etude théorique et expérimentale d’un nouveau concept d’antenne VHF miniature et accordable par décharge plasma. PhD thesis, ISAE-Supaéro, 201
Lillian L. Lambert, Author, Speaker, and Entrepreneur
No full textLillian L. Lambert, Author, Speaker, and Entrepreneu
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