1,720,966 research outputs found
Effects of scale in spatial interaction models
No full textWe study the e ects of aggregation on four di erent cases of non linear spatial
gravity models. We present some theoretical results on the relationship between
the mean
ows at an aggregated level and the mean
ow at the disaggregated
level. We then focus on the case of perfect aggregation (scale problem) showing
some results based on the theoretical expressions previously derived and on some
arti cial data. The main aim is to test the e ects on the aggregated
ows on the
spatial dependence observed in the origin and in the destination variables. We show
that positive spatial dependence in the origin and destination variables moderate
the increase of the mean
ows connatural with aggregation while negative spatial
dependence exacerbates it
Nuovi indicatori e modelli interpretativi dell’inserimento dei laureati nel mercato del lavoro dipendente e parasubordinato
No full text
Effects of MAUP on spatial econometric models
No full textAggregation effect, Loss in efficiency, MAUP, SARAR models, Scale effect, Spatial econometric, C21, C31, C5,
Unbiased estimation strategies for respondent driven sampling
Full text linkIn this paper, we focus on respondent-driven sampling (RDS), which is a valuable survey methodology to estimate the size and the characteristics of hidden or hard-to-measure population groups. The RDS methodology makes it possible to gather information on these populations by exploiting the relationships between their components. However, RDS suffers from the lack of an estimation methodology that is sufficiently robust to accommodate the varying conditions under which it is applied. In this paper, we address the estimation problem of the RDS methodology and, by approaching it as a particular indirect sampling technique, we propose three unbiased estimation methods as possible solutions
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
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