104,914 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Heteroskedasticity-Autocorrelation Robust Standard Errors Using the Bartlett Kernel without Truncation
Get PDFIn this paper we analyze heteroskedasticity-autocorrelation (HAC) robust tests constructed using the Bartlett kernel without truncation. We show that while such an HAC estimator is not consistent, asymptotically valid testing is still possible. We show that tests using the Bartlett kernel without truncation are exactly equivalent to recent HAC robust tests proposed by Kiefer, Vogelsang and Bunzel (2000, Econometrica, 68, pp 695-714).
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Weak efficiency and information in foreign exchange markets
No full textIn this paper we test the efficiency hypothesis in financial market. A market
is called efficient if the price variations "fully reflect" relevant information, i.e.
a speculator cannot make a profit out of it. A currency exchange market is a
natural candidate to check efficiency because of its high liquidity. We perform a
statistical study of weak efficiency in Deutschemark/US dollar exchange rates using
high frequency data. In the weak form of efficiency the information can only come
from historical prices.
The presence of correlations in the returns sequence implies the possibility of a
statistical prevision of market behavior. We show the existence of correlations by
means two statistical tools. A first analysis has been performed using structure
functions. This approach gives an indication on the returns distributions at
different lags \tau. We have also computed the generalized correlation functions of
the return absolute values; roughly speaking this is a test of the independence of
the fluctuations of fixed size. In both cases we have obtained a clear evidence of long
term return anomalies. This implies a failure of the usual "random walk" model
of the returns; nevertheless the presence of long term correlations does not directly
imply the fault of the weak efficiency hypothesis : it is not obvious how to use time
correlation to make a profit in a realistic investment.
Then we show how this information is relevant for a speculator. First we
introduce a measure of the available information relevant from a financial point
of view, with a technique which reminds the Kolmogorov e-entropy. Second in the
case of no transaction costs, we propose a simple investment strategy which leads
to an exponential growth rate of the capital related to the available information.
We have performed two kind of information analysis in the return series. We
show that the available information is practically zero if the speculator wants to
change his portfolio systematically after a fixed lag \tau : for him the market is efficient.
Instead, a finite available information is observed by a patient investor who cares
only of fluctuation of given size \Delta. This is the first case, as far as we know, in which
the available information obtained by a suitable data analysis is directly linked to
the possible earnings of a speculator who follows a particular trading rul
Weltliterarisches Panoptikum. Goethe und die mailändische Zeitschrift L'Eco
No full textNell’elaborazione del concetto di Weltliteratur, lo scambio che si realizza tramite i periodici è agli occhi di Goethe essenziale. E’ perciò che nel secondo volume della rivista Ueber Kunst und Alterthum lo scrittore di Weimar dedica alcuni contributi a riviste straniere. Fra queste prende in considerazione la rivista milanese Eco (1824-1835). Sulla base di alcune lettere inedite conservate all’archivio Goethe e Schiller di Weimar si ricostruisce lo scambio epistolare fra lo scrittore di Weimar e gli intellettuali milanesi, la qual cosa offre occasione per osservare l’attenzione di Goethe alla propria ricezione e, nello stesso tempo, il modo in cui la sua opera transita, nelle pagine di un periodico, nel mondo della cultura italiana
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Endogenous fertility and development traps with endogenous lifetime
Get PDFWe extend the literature on endogenous lifetime and economic growth by Chakraborty (2004) and Bunzel and Qiao (2005) to endogenous fertility. It is shown that development traps due to under investments in health can never appear when fertility is an economic decision variable.Endogenous fertility; Health; Life expectancy; OLG model
Contribution of Information and Communication Technology (ICT) in Country’S H-Index
Get PDFThe aim of this study is to examine the effect of Information and Communication Technology (ICT) development on country’s scientific ranking as measured by H-index. Moreover, this study applies ICT development sub-indices including ICT Use, ICT Access and ICT skill to find the distinct effect of these sub-indices on country’s H-index. To this purpose, required data for the panel of 14 Middle East countries over the period 1995 to 2009 is collected. Findings of the current study show that ICT development increases the H-index of the sample countries. The results also indicate that ICT Use and ICT Skill sub-indices positively contribute to higher H-index but the effect of ICT access on country’s H-index is not clear
Fully Turbulent Mean Velocity Profile for Purely Viscous non-Newtonian Fluids
No full textThe characteristic near wall behavior of turbulent flow of purely-viscous non-Newtonian fluids is discussed for both power-law (P.-L.) and Herschel-Bulkley (H.-B.) rheological models. A proper scaling is presented for H.-B. fluids to establish an analogy with power-law fluids with same flow index. To provide reference data for turbulent flow of non-Newtonian fluids, DNS simulations of power-law fluids are conducted in a rectangular channel for a large range of power-law indices ( = 0.5, 0.69, 0.75, 0.9, 1, 1.2). The DNS data show that the mean velocity profile in the viscous and logarithmic layers follow expressions of the form and respectively, where shows a logarithmic dependency on the flow index.Comparison with some experimental data shows the above formulation to be valid for Reynolds numbers (based on shear velocity) as high as 1000
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