1,720,979 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
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
Reconstructing arithmetic formulas using lower bound proof techniques
No full textWhat is the smallest formula computing a given multivariate polynomial f(x)=
In this talk I will present a paradigm for translating the known lower
bound proofs for various subclasses of formulas into efficient proper learn=
ing algorithms for the same subclass.
Many lower bounds proofs for various subclasses of arithmetic formulas redu=
ce the problem to showing that any expression for f(x) as a sum of =93simpl=
e=94 polynomials T_i(x):
f(x) =3D T_1(x) + T_2(x) + =85 + T_s(x),
the number s of simple summands is large. For example, each simple summand =
T_i could be a product of linear forms or a power of a low degree polynomia=
l and so on.
The lower bound consists of constructing a vector space of linear maps M, e=
ach L in M being a linear map from the set of polynomials F[x] to some vect=
or space W
(typically W is F[X] itself) with the following two properties:
(i) For every simple polynomial T, dim(M*T) is small, say =
that dim(M*T) <=3D r.
(ii) For the candidate hard polynomial f, dim(M*f) is large,=
say that dim(M*f) >=3D R.
These two properties immediately imply a lower bound: s >=3D R/r.
The corresponding reconstruction/proper learning problem is the following: =
given f(x) we want to find the simple summands T_1(x), T_2(x), =85, T_s(x) =
which add up to f(x).
We will see how such a lower bound proof can often be used to solve the rec=
onstruction problem. Our main tool will be an efficient algorithmic solutio=
n
to the problem of decomposing a pair of vector spaces (U, V) under the simu=
ltaneous action of a vector space of linear maps from U to V.
Along the way we will also obtain very precise bounds on the size of formul=
as computing certain explicit polynomials. For example, we will obtain for =
every s, an explicit
polynomial f(x) that can be computed by a depth three formula of size s but=
not by any depth three formula of size (s-1).
Based on joint works with Chandan Saha and Ankit Garg.Non UBCUnreviewedAuthor affiliation: MSR IndiaFacult
Arithmetic Circuit Complexity (Tutorial)
No full textArithmetic Circuits compute polynomial functions over their inputs via a sequence of arithmetic operations (additions, subtractions, multiplications, divisions, etc.). This tutorial will give an overview of arithmetic circuit complexity, focusing on the problem of proving lower bounds for arithmetic circuits.
In the first part, we begin with a few nontrivial upper bounds - matrix multiplication and the computation of symmetric polynomials. We then motivate some open problems we deal with in arithmetic circuit complexity. We will look at the problem of polynomial identity testing - motivating it by its application to bipartite matching, the problem of learning arithmetic circuits or circuit reconstruction and the problem of proving lower bounds for arithmetic circuits (motivating it via the problem of computing the permanent and the Hamiltonian polynomials). We will also see depth reduction for circuits - the tradeoffs involved (with respect to size) in squashing a circuit into one with smaller depth.
In the second part, we will see some classical lower bounds. In particular, we will see lower bounds for monotone arithmetic circuits and multilinear formulas. We then give a very quick overview of approaches being investigated (including geometric complexity theory and tau-conjecture) aiming to prove lower bounds.
In the third part, we begin with a warm-up by proving lower bounds for homogeneous depth three circuits. We will then see recent lower bounds for homogeneous depth four circuits and its consequences
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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