1,721,041 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
Fourier Dönüşüm Kızılötesi Spektroskopisi Kullanarak Proteinlerin Çözelti İçindeki Formları ile Kanser Teşhisi Uygulamalarında İnsan Sıvılarınının Biyofiziksel Karakterizasyonu
No full textProteins play very important roles in cells regulation and structure. Understanding of proteins structures greatly help in understanding of the mechanism of action of these proteins. The optical spectroscopic techniques such as Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy can be used to study proteins in its native environment without complicated sample preparations that is required for a high resolution technique such as x-ray. In order to calculate the protein secondary structure from amide I band in FTIR spectra, different methods can be used such as curve fitting and deconvolution. However, these techniques have some disadvantages due to the noise and dependence on the operator. In this study, a protein FTIR dataset of known proteins structures was produced using FTIR transmission mode. This database was used as a training set for an artificial neural networks (ANNs). Because of the limited number of our proteins in the dataset (35 proteins), a leave-one-out approach for training and testing our neural networks was performed. To achieve generalized ANNs in a limited number proteins dataset, discrete wavelet transform (DWT) was successfully used as a data reduction technique for amide I spectra. The results of ANNs predictions showed 96.88%, 93.92% and 95.98% success in β-sheets, α-helix and other structures respectively. In the second part of this thesis, Human Apo- and Holo-transferren structure and their thermal denaturation behavior in dilute and artificial crowded environment was studied using FTIR spectroscopy. Dextran 70 and Ficoll 70 as a “molecular crowder” did not have a major effect on the secondary structure of transferrin as deduced from the analysis of the amide I band. However, it does alter the tertiary structure since significant differences in hydrogen-deuterium exchange was seen by monitoring the intensity of the residual amide II band as a function of time. The study of transferrin thermal denaturation using 2D-IR showed two different aggregated secondary structures patterns in dilute and in an artificial crowded environment. Finally, the proteins secondary structure of human pleural fluid accumulated due to malignant pleural mesothelioma (MPM), lung cancer (LC) and benign transudate (BT) was studied using attenuated total reflectance FTIR spectroscopy. Wavelet analysis was performed to extract the amide I spectral features. The extracted features were used as an input for the previously trained artificial neural network in the first part of this thesis. The ANNs results indicated significant differences in protein content of BT, LC and MPM pleural fluid samples. The chemometric results of the plural fluid proteins secondary structure lead to an accurate, cost effective method for the diagnosis of MPM from lung cancer and benign transudate with 88% sensitivity and 100% specificity.Ph.D. - Doctoral Progra
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
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
uzay-zaman uyarlamalı işlemci kullanarak karıştırıcı bastırılması.
Full text linkSpace-Time Adaptive Processing (STAP) has been widely used in spaceborne and airborne radar platforms in order to track ground moving targets. Jammer is an hostile electronic countermeasure that is being used to degrade radar detection and tracking performance. STAP adapts radar’s antenna radiating pattern in order to reduce jamming effectiveness. Jamming power that enters the system is decreased with respect to the adapted radiation pattern. In this thesis, a generic STAP radar model is developed and implemented in simulation environment. The implemented radar model demonstrates that, STAP can be used in order to suppress wideband jammer effectiveness together with ground clutter effects.M.S. - Master of Scienc
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