1,720,958 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
Regression Analysis and Indicator Variables
Full text linkRegression analysis is statistical model that is concerned with describing and evaluating
the relationship between a given variable known as dependent variable and
one more other variable known as independent variable.
The present thesis entitled “Regression Analysis and Indicator Variables”.
This exposition comprises four chapters and each chapter is divided into various subsections.
Chapter 1 includes introduction about Bivariate distribution. The main focus is
on knowing the nature and relationship between two these variables. In this chapter
there are two techniques used for this, one is correlation analysis and other is
regression analysis.
In Chapter 2, simple linear regression is discussed. The main focus in this chapter
is on least squares-fit to estimate the model parameters. This chapters includes
definition of simple linear regression, examples, properties of least squares estimators
and the fitted regression model, estimation of σ
2
, hypothesis testing on model
parameters, use of t-tests, testing significance of regression, analysis of variance and
coefficient of determination.
In Chapter 3, we have discussed multiple linear regression. In this chapter, we have
done least squares-estimation of model parameters as described in Chapter 2. This
chapters includes basic definition of multiple linear regression, examples, properties
of least-square estimators, estimation of σ
2
, testing significance of regression, test on
individual regression coefficients and coefficient of determination- R2 and adjusted
R2
.
Chapter 4 contains introduction about indicator variables. This chapter includes
example of indicator variable, an indicator variable with more than two levels, more
than one indicator variable
Electrochemical Behavior of Metallic Coatings Containing Carbonaceous Additives
No full textCoatings have been traditionally used for protection against corrosion. Therefore, substantial efforts have been focused on engineering the microstructure and morphology of coatings to enhance their corrosion resistance performance. It has been shown recently that incorporation of carbonaceous additives such as graphene, graphene oxide, and carbon nanotubes (CNTs) into conventional metallic coatings has produced composite coatings with significantly enhanced corrosion resistance behavior. It is believed that the observed enhancement in the corrosion resistance is essentially due to the inertness and impermeability of graphene/graphene oxide (GO) and hydrophobicity of the CNTs. In this thesis, it is shown that in addition to the above factors, microstructural alterations in the metallic coatings due to the incorporation of carbonaceous additives also play a major role in deciding the corrosion properties of the coatings. The electrodeposited coating systems that have been explored in the present work are: NiCo-graphene oxide, NiCo-carbon nanotube, ZnCo-graphene oxide, ZnCo-carbon nanotube, and ZnMn-graphene oxide composite coatings. In all the cases, the corrosion rate was found to be very sensitive to the amount of additive present in the coatings. With increasing GO/CNT content, the corrosion rate first decreased to a minimum value followed by sudden increase to values higher than the pristine coating.
In the NiCo-graphene oxide composite coating work, microstructural examination of the coatings revealed that the “optimum” content of GO which yielded minimum corrosion rate produced a unique microstructure with highest fraction of low angle grains boundaries and lowest fraction of incoherent twin boundaries when compared to all other composite coatings. In the NiCo-CNT composite coating work, the corrosion rate was found to be sensitive to the amount of the additive and an optimum concentration of CNT in the coating matrix yielded high corrosion resistance behavior. This CNT concentration produced microstructure with coating growth along the low energy (111) direction with largest fraction of low energy low angle grain boundaries. In the ZnCo-GO composite coatings work, it was shown that an optimum addition of graphene oxide in ZnCo coatings yields high corrosion resistance performance. Decrease in the corrosion rate was attributed to impermeability of the graphene oxide and enhancement in the relative volume fraction of the Zn10.63Co2.34 intermetallic phase. In case of the ZnCo-CNT composite coatings, the electrochemical measurements showed that the corrosion rate of the ZnCo-CNT composite coatings decreased for initial addition of CNTs to reach a minimum for an “optimum” CNT concentration, after which it increased with further excess CNT addition. The enhancement in the corrosion rate was attributed to compact surface morphology and highest intermetallic (Zn10.63Co2.34) phase fraction. In the case of ZnMn-GO composite coatings the corrosion resistance was again observed to be sensitive to the amount of GO contained in the coatings. It was observed that the incorporation of GO produced alteration in the growth texture of the Zn0.73Mn0.27 intermetallic phase in the coating matrix which enhanced the corrosion behavior of the ZnMn-GO composite coatings.
Key conclusions derived from the work presented in this thesis are: (a) there exists an optimum concentration of the carbonaceous additives at which the corrosion resistance of the composite coatings is maximum. Before the optimum, alteration in coating microstructure and phase constitution govern the electrochemical behavior. Microstructural alterations such as increase in low angle grain boundaries and increase in the fraction of relatively stable phase decrease the corrosion rate, (b) morphology of the composite coatings tends to get smoother with lesser surface defects with increase in the additive amount till the optimum. Beyond the optimum, the morphology becomes rough with defects and cracks which appear primarily due to the agglomeration of the additives. Decrease in surface roughness increases the corrosion rate till the optimum and increase in surface defects for higher additive additions increases the corrosion rate, (c) the galvanic coupling between carbonaceous additives and the metallic matrix becomes prominent at higher additions of carbonaceous material due to substantial increase in cathode/anode area ratio. This galvanic coupling deteriorates the corrosion rate at higher additions. At lower carbon additive amounts the galvanic coupling is not very prominent because of small cathode/anode ratio. At lower carbonaceous additions, the changes in the coating microstructure is prominent in determining the corrosion rate.Science and engineering research board (SERB) , Council of scientific and industrial research (CSIR
Reduction of Switching Transients in Constant Current (CC)/Constant Voltage (CV) Mode of Electric Vehicles Battery Charging
No full textOptimum charging of electric vehicles is of great interest today. Researchers have worked upon different charge methodology for switching from constant current mode (CCM) to con- stant voltage mode (CVM). But, major problem occurs while transition are the switching tran- sients. Therefore, a suitable methodology for switching from CCM to CVM while charging the lithium-ion battery is to be implemented. Among the various methods used today, Schmitt trigger switching is the most reliable and efficient method for charging the lithium-ion battery. Therefore, this work adopts CCM/CVM mode of charging with Schmitt trigger switching. This helps in reducing switching losses and increasing the response time of the battery. For imple- menting the proposed scheme, a hardware for the boost converter is designed and the control- ling for the same is obtained using Opal-RT. PI controller for CCM and CVM is designed to regulate the output and generate the desired duty cycle.
Tuning of the PI controller for CCM and CVM is obtained using loop shaping method. Switching between the two modes i.e. CCM and CVM is done using Schmitt trigger. The band limit of Schmitt trigger is set according to the capacitor ripple voltage. The controlling param- eter i.e. the duty cycle generated is applied to the IGBT switches using digital I/Os. The input parameters voltage and current are feedback using analog I/Os. Thus, the real-time results for battery charging i.e. voltage and current can be obtained accordingly
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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