1,721,551 research outputs found
Taming the Spread of an Epidemic by Lockdown Policies
Full text linkFederico S, Ferrari G. Taming the Spread of an Epidemic by Lockdown Policies. Center for Mathematical Economics Working Papers. Vol 639. Bielefeld: Center for Mathematical Economics; 2020.We study the problem of a policymaker who aims at taming the spread of an epidemic
while minimizing its associated social costs. The main feature of our model lies in the fact that the
disease's transmission rate is a diffusive stochastic process whose trend can be adjusted via costly
confinement policies. We provide a complete theoretical analysis, as well as numerical experiments
illustrating the structure of the optimal lockdown policy. In all our experiments the latter is characterized
by three distinct periods: the epidemic is first let freely evolve, then vigorously tamed, and
finally a less stringent containment should be adopted. Moreover, the optimal containment policy is
such that the product "reproduction number x percentage of susceptible" is kept after a certain date
strictly below the critical level of one, although the reproduction number is let oscillate above one in
the last more relaxed phase of lockdown.MSC2010 subject classification: 93E20, 49N90, 92D30, 97M4
Singular Control of the Drift of a Brownian System
Full text linkFederico S, Ferrari G, Schuhmann P. Singular Control of the Drift of a Brownian System. Center for Mathematical Economics Working Papers. Vol 637. Bielefeld: Center for Mathematical Economics; 2020.We consider a standard Brownian motion whose drift can be increased or decreased in a possibly singular manner. The objective is to minimize an expected functional involving the time-integral of a running cost and the proportional costs of adjusting the drift. The resulting two-dimensional degenerate singular stochastic control problem is solved by combining techniques of viscosity theory and free boundary problems. We provide a detailed description of the problem's value function and of the geometry of the state space, which is split into three regions by two monotone curves. Our main result shows that those curves are continuously di fferentiable with locally Lipschitz derivative and solve a system of nonlinear ordinary diff erential equations.MSC2010 subject classification: 93E20, 91A55, 49L25, 49J40, 35R35, 91B6
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
Forecasting banknotes
Full text linkA central bank’s liquidity forecast is important in ensuring that it supplies the banking system’s need for central bank money. Banknote (or currency in circulation) demand is the largest and for some central banks the most variable component of the liquidity forecast. Accurate forecasting of banknotes is essential in ensuring an accurate liquidity forecast and in turn effective monetary policy implementation. This Handbook discusses these issues and outlines a structural time series state space (STSSS) model which is now used by central banks including the Bank of England and ECB to forecast banknotes (currency in circulation).Forecasting banknotes
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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