11,903 research outputs found
Network-based ranking in social systems: three challenges
Ranking algorithms are pervasive in our increasingly digitized societies,
with important real-world applications including recommender systems, search
engines, and influencer marketing practices. From a network science
perspective, network-based ranking algorithms solve fundamental problems
related to the identification of vital nodes for the stability and dynamics of
a complex system. Despite the ubiquitous and successful applications of these
algorithms, we argue that our understanding of their performance and their
applications to real-world problems face three fundamental challenges: (i)
Rankings might be biased by various factors; (2) their effectiveness might be
limited to specific problems; and (3) agents' decisions driven by rankings
might result in potentially vicious feedback mechanisms and unhealthy systemic
consequences. Methods rooted in network science and agent-based modeling can
help us to understand and overcome these challenges.Comment: Perspective article. 9 pages, 3 figure
Review of Reactor Neutrino Oscillation Experiments
In this document we will review the current status of reactor neutrino
oscillation experiments and present their physics potentials for measuring the
neutrino mixing angle. The neutrino mixing angle is
currently a high-priority topic in the field of neutrino physics. There are
currently three different reactor neutrino experiments, \textsc{Double Chooz},
\textsc{Daya Bay} and \textsc{Reno} and a few accelerator neutrino experiments
searching for neutrino oscillations induced by this angle. A description of the
reactor experiments searching for a non-zero value of is given,
along with a discussion of the sensitivities that these experiments can reach
in the near future.Comment: 15 pages, 4 figure
Gaucher Disease and Myelofibrosis: A Combined Disease or a Misdiagnosis?
Background: Gaucher disease (GD) and primary myelofibrosis (PMF) share similar clinical and laboratory features, such as cytopenia, hepatosplenomegaly, and marrow fibrosis, often resulting in a misdiagnosis. Case Report: We report here the case of a young woman with hepatosplenomegaly, leukopenia, and thrombocytopenia. Based on bone marrow (BM) findings and on liver biopsy showing extramedullary hematopoiesis, an initial diagnosis of PMF was formulated. The patient refused stem cell transplantation from an HLA-identical sibling. Low-dose melphalan was given, without any improvement. Two years later, a BM evaluation showed Gaucher cells. Low glucocerebrosidase and high chitotriosidase levels were indicative for GD. Molecular analysis revealed N370S/complex I mutations. Enzyme replacement therapy with imiglucerase was commenced, resulting in clinical and hematological improvements. Due to an unexpected and persistent organomegaly, PMF combined with GD were suspected. JAK2V617F, JAK2 exon 12, MPL, calreticulin, and exon 9 mutations were negative, and BM examination showed no marrow fibrosis. PMF was excluded. Twenty years after starting treatment, the peripheral cell count and liver size were normal, whereas splenomegaly persisted. Conclusion: In order to avoid a misdiagnosis, a diagnostic algorithm for patients with hepatosplenomegaly combined with cytopenia is suggested
Accounting Control Systems, Open Innovation and Sustainable Competitive Advantage
The purpose of the study is to study whether management accounting and control systems (MACS) and intellectual capital (IC) reflect the sustainability competitive advantage (SCA) of the companies concerned. Where a greater focus on open innovation occurs, it may require a different emphasis on management accounting practices compared to companies where they do not feature strongly. It is assumed to be important that management recognise and act on this in order to improve firms’ sustainability competitive advantage. This study is expected to show that the level of open innovation (OI), as expected to be a major source of corporate competitive advantage, influences the practice of management accounting and control systems and intellectual capital. Whilst the literatures place considerable attention on (close) innovation purposes, far less attention has been given so far to the implications of open innovation for managerial accounting practice. This research addresses this omission. The methodology of this study is a literature review.
Keywords: open innovation, management accounting and control systems, intellectual capital, sustainable competitive advantage, pharmaceutical company
Principal Component Analysis of RR Lyrae light curves
In this paper, we analyze the structure of RRab star light curves using
Principal Component Analysis. We find this is a very efficient way to describe
many aspects of RRab light curve structure: in many cases, a Principal
Component fit with 9 parameters can describe a RRab light curve including bumps
whereas a 17 parameter Fourier fit is needed. As a consequence we show
statistically why the amplitude is also a good summary of the structure of a RR
Lyrae light curve. We also use our analysis to derive an empirical relation
relating absolute magnitude to light curve structure. In comparing this formula
to those derived from exactly the same dataset but using Fourier parameters, we
find that the Principal Component Analysis approach has disticnt advantages.
These advantages are, firstly, that the errors on the coefficients in such
formulae are smaller, and secondly, that the correlation between Principal
Components is significantly smaller than the correlation between Fourier
amplitudes. These two factors lead to reduced formal errors, in some cases
estimated to be a factor of 2, on the eventual fitted value of the absolute
magnitude. This technique will prove very useful in the analysis of data from
existing large scale survey projects concerning variable stars.Comment: 8 pages, 10 figures, revised version, accepted for publication to
MNRA
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