117,284 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
Nanorakenteiden ja fotoniikan komponenttien uudet valmistustekniikat
No full textThis thesis introduces novel micro- and nanofabrication methods and their applications developed in Micronova, the clean room facilities of Aalto University. The work is performed with silicon, which is robust, stable, and easy to process material with good electrical and optical properties. The developed fabrication methods facilitate technologically challenging types of nanostructures and their fabrication on non-planar surfaces.
The presented research consists of two parts. The first part is focused on nanofabrication, mostly via top-down fabrication approach. The second one describes the modification of photonic devices and waveguides by \mbox{atomic-layer-deposited} thin films. The three main types of processing involved in the thesis are: atomic layer deposition, exposure by focused ion beam, and dry etching.
As a result of this study, several fabrication methods were developed. One of them utilizes focused ion beam lithography for nanofabrication on multilevel and strongly corrugated surfaces. This process has a great potential for general 3D integration and for micro- and nanofluidics. The same approach enables the fabrication of suspended nanostructures and gives a platform for accurate measurement of material properties and realization of lab-on-a-chip concepts. Another separately developed process is a grayscale lithography that provides a control over the height of patterned features at nanometer scale. It gives an effective way to fabricate miniature diffractive optics components for extreme ultraviolet and soft X-ray radiation. It also allows for new designs and improved performance of photonic grating couplers. Finally, the work shows how atomic layer deposition can be used to tune the operational parameters of photonic components. In particular, the dispersion properties of photonic nanostrip waveguides were optimized, and micro ring resonators were tuned towards polarization-independent regime in a broad wavelength range.
In summary, the work extends the applications of nanotechnology for sensing and integrated optics. The shown nanofabrication methods provide fast prototyping due to the minimized number of process steps. Atomic layer deposition of thin films was demonstrated to be very effective for tuning of photonic waveguides and devices. The presented techniques and methods have a showcase character and provide a room for further research focused on other materials and applications.Tässä väitöskirjassa tarkastellaan Aalto-yliopiston Micronova-puhdastilaympäristössä kehitettyjä uusia mikro- ja nanotekniikan valmistusmenetelmiä ja niiden sovelluksia. Valmistusmateriaaliksi valittiin pii, koska se on kestävä ja stabiili materiaali, jolla on suotuisat sähköiset ja optiset ominaisuudet ja jota on verrattain helppo prosessoida.
Työ koostuu kahdesta osasta. Ensimmäinen osa käsittelee nanovalmistusta, pääosin ns. "topdown"-valmistustekniikoita, joihin kuuluu menetelmiä, joilla materiaalia poistetaan ennalta suunnitellun kuvion mukaisesti. Toisessa osassa tutkitaan fotoniikan komponenttien ominaisuuksien räätälöintiä atomikerroskasvatettujen ohutkalvojen avulla. Tässä tutkimustyössä on kolme keskeistä prosessia: atomikerroskasvatus, fokusoidun ionisuihkun avulla suoritettu kuviointi ja kuivaetsaus.
Tutkimuksen tuloksena on kehitetty useita piimateriaalin muokkaamiseen tarkoitettuja valmistusmenetelmiä. Merkittävä osa tuloksista saatiin hyödyntämällä fokusoidun ionisuihkun (FIB) avulla suoritettua litografiaa, jolloin oli mahdollista saada aikaan nanorakenteita myös epätasaisille ja kalteville pinnoille. Tätä prosessia voi hyödyntää sekä 3Dintegraatiossa että mikro- ja nanofluidistiikassa. Samoja periaatteita voidaan soveltaa myös vapautettujen nanorakenteiden valmistamiseen. Tämäntyyppisiä rakenteita käytetään mm. materiaalien ominaisuuksien tutkimuksissa ja "lab-on-a-chip"- sovelluksissa. Tutkimuksessa on myös kehitetty fokusoidun ionisuihkun käyttöön perustuva ns. "harmaasävy"- litografia, jolla kyetään aikaansaamaan erilaisia nanorakenteiden korkeusprofiileja. Tätä menetelmää voi käyttää pienten integroitujen diffraktiivisen optiikan komponenttien valmistukseen, jotka toimivat ultraviolettiaallonpituuksilla. Työssä kehitetty litografia mahdollistaa uuden tavan tehdä piipohjaisia fotoniikan hilakytkimiä. Lisäksi tässä väitöskirjassa esitellään tapoja käyttää atomikerroskasvatusta fotoniikassa aaltojohteiden ja mikroresonaattorien virittämiseen esimerkiksi siten, että niiden toiminta on polarisaatiosta riippumatonta.
Tässä työssä saavutetut tulokset laajentavat nanoteknologian mahdollisuuksia sekä nanorakenteiden valmistamisessa että optiikan sovelluksissa. Kehitetyissä valmistusmenetelmissä prosessivaiheiden määrä on minimoitu, joten ne sopivat erityisesti prototyyppien valmistamiseen. Työssä esitetään myös suuntaviivoja miten näitä kehitettyjä perustekniikoita voisi jatkossa edelleen tehostaa
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
Lillian L. Lambert, Author, Speaker, and Entrepreneur
No full textLillian L. Lambert, Author, Speaker, and Entrepreneu
Letter to Alfred L. Shoemaker, February 10, 1948
No full textA handwritten letter from an unknown author addressed to Alfred L. Shoemaker, dated February 10, 1948. Within, the author discusses the Pennsylvania Dutch word for Ash Wednesday, along with traditions associated with this day.https://digitalcommons.ursinus.edu/shoemaker_documents/1118/thumbnail.jp
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Emmett L. Bennett, Jr. Offprint Collection
No full textThe scholarly library of Emmett L. Bennett, Jr. compiled in the course of his Editorship of the journal Nestor (founded in 1957). The collection includes scholarly publications (offprints) and manuscripts sent by prospective authors to Dr. Bennett. Includes a Finding Aid (PDF and Word) and Catalog (an Excel document for each of two record groups: offprints collected up to 1995, and offprints collected from 1995-2011). Both the Finding Aid and Catalog are provided to facilitate researchers' searches for offprints by author, title, journal, year, and subject.Classic
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