1,721,075 research outputs found
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Atıf Efendi Library
No full textTaha Toros Arşivi, Dosya No: 111-Kütüphanelerİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033
Gamma Rays Absorption Properties of Some Graphene-Doped Concrete
No full textBu tez çalışması kapsamında 3 farklı beton üretilmiştir. Üretilen betonlardan normal betonda agrega
olarak standart kum, çimento ve su kullanılmıştır. Diğer 2 beton türünde ise %2 ve %4 oranında çimento ile
yer değiştirmek suretiyle grafen oksit kullanılmıştır. Üretilen betonların radyasyon geçirgenlik deneyleri
Süleyman Demirel Üniversitesi Fen-Edebiyat Fakültesi Fizik Bölümü Nükleer Fizik A.B.D. Gamma
Spektroskopi Laboratuvarında bulunan NaI(Tl) detektörlü gama spektroskopi sistemi kullanılarak yapılmıştır.
Ölçümler sonucunda doğrusal zayıflatma katsayısı (μ) sonuçları 137Cs ve 60Co radyoaktif kaynaklarından
yayınlanan 662, 1173 ve 1332 keV gama enerjileri için elde edilmiştir. Doğrusal zayıflatma katsayısı sonuçları
kullanılarak ortalama serbest yol (MFP) ile yarı değer ve onda bir değer kalınlıkları parametreleri
hesaplanmıştır.Within the scope of this thesis, 3 different concretes were produced. Standard sand, cement and water
were used as aggregates in normal concrete from the produced concretes. In the other 2 concrete types, graphene
oxide was used by replacing 2% and 4% cement with cement. Radiation permeability tests of produced
concretes Süleyman Demirel University Faculty of Arts and Sciences Department of Physics Nuclear Physics
Department. It was done by using gamma spectroscopy system with NaI(Tl) detector in the Gamma
Spectroscopy Laboratory. As a result of the measurements, linear attenuation coefficient (μ) results were
obtained for 662, 1173 and 1332 keV gamma energies broadcast from 137Cs and 60Co radioactive sources.
Using the linear attenuation coefficient results, mean free path (MFP) and half value and one-tenth value
thickness parameters were calculated
Investigation of Paramagnetic Properties of Tooth Enamel Sample Using Electron Spin Resonance (ESR) Method
No full textHidroksiapatit, diş minesinin mineral kısmının ana bileşenidir. Bu yapıda karbonat iyonları gibi
bazı safsızlıklar kuvvetli bir şekilde gözlenebilir. İyonlaştırıcı radyasyon hidroksiapatit tarafından
emildiğinde, radyasyondan dolayı birkaç paramanyetik tür oluşabilir. Bu nedenle, bu radikal türlerinin
hidroksiapatit yapısındaki değişikliklerdeki rolünü anlamak için çeşitli spektroskopik teknikler
kullanılmaktadır. Elektron spin rezonans (ESR), paramanyetik radikalleri araştırmak için kullanılan bir
manyetik rezonans tekniğidir. Radyasyona bağlı radikallerin konsantrasyonu genellikle radyasyon dozu ile
orantılıdır ve ESR bu radikalleri ölçmek için kullanılan en hassas yöntemlerden biridir.
Bu çalışmada, gama ışınları ile ışınlanmış arkeolojik diş minesi üzerinde ESR analizleri yapılmış
ve paramanyetik radikaller belirlenmiştir. Burada, uygun ESR ölçümlerinin yapılabilmesi amacıyla diş
minesi numunesi mineyi ayırma, temizleme ve mekanik olarak öğütme aşamalarını içerecek şekilde
hazırlanmıştır. Numune hazırlama işleminden sonra elde edilen mine parçaları 60Co-gamma kaynağı ile
yapay olarak ışınlanmış ve daha sonra elde edilen uygun spektrometre koşulları ile X-Band ESR
spektrometresi kullanılarak oda sıcaklığında spektrumları kaydedilmiştir. Elde edilen tüm spektrum
sonuçları, ışınlama ile diş minesinde anizotropik g değerlerine ve eksensel bir simetriye sahip kararlı CO2
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radikalinin oluştuğunu göstermiştir. Ayrıca, ESR spektrumları, radikal merkezinden kaynaklanan sinyal
genliklerinin radyasyon dozlarının bir fonksiyonu olarak büyüdüğünü ortaya çıkarmıştır.The hydroxyapatite is the main constituent of the mineral part of tooth enamel. In this structure,
some impurities such as carbonate ions can be observed strongly. When ionizing radiation is absorbed in
hydroxyapatite, several paramagnetic species can occur due to radiation. So, various spectroscopic
techniques are used to the understanding of the role of these radical species in the changes of hydroxyapatite
structure. The electron spin resonance (ESR) is a magnetic resonance technique which is used to investigate
the paramagnetic radicals. The concentration of radiation-induced radicals is generally proportional to the
radiation dose and ESR is the most sensitive method to measure these radicals.
In this work, ESR analyses were performed on gamma irradiated archaeological tooth enamel and
paramagnetic radicals were determined. For this purpose, tooth enamel sample was prepared for making
suitable ESR measurements with including the following steps: separation, cleaning and grinding
mechanically enamel. After sample preparation, obtained samples were irradiated by 60Co-gamma source
artificially and then ESR measurements were carried out at room temperature using X-Band ESR
spectrometer with obtained optimal spectrometer conditions. The results of all obtained spectra showed that
the stable CO2
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radical which has anisotropic g values and an axial peak was generated in the tooth enamel
by irradiation. Moreover, the ESR spectra revealed that the signal amplitudes due to the radical center were
growing up as a function of radiation doses
Investigation of Paramagnetic Centers Created in Some Chemical Structures by Gamma Rays Using Electron Spin Resonance (ESR) Method
No full textBu çalışmada gama ışınlarına tutulan Cerium Ammonium Nitrate polikristal örneğinin elektron
paramanyetik rezonans sinyalleri gözlendi ve alınan spektrumlar analiz edildi. ESR
parametreleri bulundu. Cerium Ammonium Nitrate polikristalleri 130-450.K sıcaklık
aralığında incelendi ve Cerium Ammonium Nitrate polikristalinin ESR spektrumunun sıcaklığa
bağlı olduğu bulundu.In this work, the electron spin resonance signals of Cerium Ammonium Nitrate polycrytal
samples irradiated by gamma source have been observed and obtained the spectra have been
analyzed. a and g ESR parameters were found. The polycrystals have been investigated
between 130 – 450.K, and the spectra of Cerium Ammonium Nitrate crystals were found to be
dependent on temperature
Radiation shielding properties of some glass samples
No full textRadyasyon teknolojinin gelişmesi ile birlikte hayatımızın geniş bir alanında kullanılmaya başlanmıştır. Tıpdan enerji sektörüne kadar her alanda kullanılan radyasyonun yüksek dozlarda kullanılması olası sağlık sorunlarını da beraberinde getirmektedir. Bu nedenle radyasyondan korunma bilim insanları açısından önemli bir konu olmuş ve bu alandan önemli çalışmalar yapılmaktadır. Bu tez çalışmasında radyasondan korunmak için önemli olan zırh malzemesi olarak bazı camların radyasyon soğurma özellikleri araştırılıp sonuçlar tartışılacaktırRadiation has started to be used in a wide area of our lives with the development of technology. The use of radiation in high doses, which is used in every field from medicine to the energy sector, also brings about possible health problems. For this reason, radiation protection has become an important issue for scientists and important studies are being carried out in this field. In this thesis, the radiation absorption properties of some glasses as armor materials, which are important for protection from radiation, will be investigated and the results will be discussed
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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