208 research outputs found
Generalized h-index for Disclosing Latent Facts in Citation Networks
What is the value of a scientist and its impact upon the scientific thinking?
How can we measure the prestige of a journal or of a conference? The evaluation
of the scientific work of a scientist and the estimation of the quality of a
journal or conference has long attracted significant interest, due to the
benefits from obtaining an unbiased and fair criterion. Although it appears to
be simple, defining a quality metric is not an easy task. To overcome the
disadvantages of the present metrics used for ranking scientists and journals,
J.E. Hirsch proposed a pioneering metric, the now famous h-index. In this
article, we demonstrate several inefficiencies of this index and develop a pair
of generalizations and effective variants of it to deal with scientist ranking
and with publication forum ranking. The new citation indices are able to
disclose trendsetters in scientific research, as well as researchers that
constantly shape their field with their influential work, no matter how old
they are. We exhibit the effectiveness and the benefits of the new indices to
unfold the full potential of the h-index, with extensive experimental results
obtained from DBLP, a widely known on-line digital library.Comment: 19 pages, 17 tables, 27 figure
Co-creation: Moving towards a framework for creating innovation in the triple helix
The objective of the paper is to demonstrate how the theoretical ideas of Service-Dominant Logic (S-D logic) can usefully be applied to innovation through collaboration between university, industry and government. The debate around S-D logic has stimulated much discussion around three areas that are particularly pertinent in considering the co-creation of knowledge within the Triple Helix. The first area relates to understanding the nature of the resources provided by all the parties involved and the process through which they are integrated. The second area relates to interaction between the parties involved. The third and most complex area relates to how value is perceived by the different parties. This discussion leads to a proposed model of the co-creation process and four suggested research agendas: Research Agenda One, relating to the resources supplied by the parties and their integration; Research Agenda Two, concerning the interaction practices that enhance co-creation; Research Agenda Three, exploring what value propositions will motivate the different parties to co-create; and Research Agenda Four, considering how co-creation modifies the resources of the parties involved. A model of the co-creation process that encompasses these four research agendas and provides a conceptual framework to analyse Triple Helix initiatives is proposed. Some practical implications are then discussed, relating to the challenges for researchers in identifying who to co-create with and understanding what value propositions will motivate potential partners
E-government adoption: A cultural comparison
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ Springer Science + Business Media, LLC 2008.E-government diffusion is an international phenomenon. This study compares e-government adoption in the U.K. to adoption in the U.S. In particular, this study seeks to determine if the same factors are salient in both countries. Several studies have explored citizen acceptance of e-government services in the U.S. However, few studies have explored this phenomenon in the U.K. To identify the similarities and differences between the U.K. and the U.S. a survey is conducted in the U.K. and the findings are compared to the literature that investigates diffusion in the U.S. This study proposes a model of e-government adoption in the U.K. based on salient factors in the U.S. A survey is administered to 260 citizens in London to assess the importance of relative advantage, trust and the digital divide on intention to use e-government. The results of binary logistic regression indicate that there are cultural differences in e-government adoption in the U.K. and the U.S. The results indicate that of the prevailing adoption constructs, relative advantage and trust are pertinent in both the U.S. and the U.K., while ICT adoption barriers such as access and skill may vary by culture. Implications for research and practice are discussed
The Effect of N-nitrosodimethylamine (NDMA) on Bax and Mcl-1 Expression in Human Neutrophils
In the present study we examined a role of pro-apoptotic Bax and anti-apoptotic Mcl-1 proteins, participating in the regulation of intrinsic apoptosis pathway in human neutrophils (PMNs) exposed to N-nitrosodimethylamine (NDMA), the environmental xenobiotic. For the purpose comparison, the same studies were conducted in autologous peripheral blood mononuclear cells (PBMCs). The production of cytochrome c by PMNs was also determined. A deficit of anti-apoptotic Mcl-1 and overexpression of the pro-apoptotic protein Bax suggest that the apoptosis process in human neutrophils exposed to NDMA is dependent on changes in the expression of these proteins. PMNs were more sensitive to NDMA than PBMCs
Impact Factor: outdated artefact or stepping-stone to journal certification?
A review of Garfield's journal impact factor and its specific implementation
as the Thomson Reuters Impact Factor reveals several weaknesses in this
commonly-used indicator of journal standing. Key limitations include the
mismatch between citing and cited documents, the deceptive display of three
decimals that belies the real precision, and the absence of confidence
intervals. These are minor issues that are easily amended and should be
corrected, but more substantive improvements are needed. There are indications
that the scientific community seeks and needs better certification of journal
procedures to improve the quality of published science. Comprehensive
certification of editorial and review procedures could help ensure adequate
procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table
Asteroids. From Observations to Models
We will discuss some specific applications to the rotation state and the
shapes of moderately large asteroids, and techniques of observations putting
some emphasis on the HST/FGS instrument.Comment: to appear in LNP; 28pages; written in 2003; Winter School "Dynamique
des Corps Celestes Non Ponctuels et des Anneaux", Lanslevillard (FRANCE
The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets
This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sunâs centre, equal to half of Mercuryâs perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics
Radar Observations and the Shape of Near-Earth Asteroid 2008 EV5
We observed the near-Earth asteroid 2008 EV5 with the Arecibo and Goldstone
planetary radars and the Very Long Baseline Array during December 2008. EV5
rotates retrograde and its overall shape is a 400 /pm 50 m oblate spheroid. The
most prominent surface feature is a ridge parallel to the asteroid's equator
that is broken by a concavity 150 m in diameter. Otherwise the asteroid's
surface is notably smooth on decameter scales. EV5's radar and optical albedos
are consistent with either rocky or stony-iron composition. The equatorial
ridge is similar to structure seen on the rubble-pile near-Earth asteroid
(66391) 1999 KW4 and is consistent with YORP spin-up reconfiguring the asteroid
in the past. We interpret the concavity as an impact crater. Shaking during the
impact and later regolith redistribution may have erased smaller features,
explaining the general lack of decameter-scale surface structure.Comment: This paper has been accepted for publication in Icarus:
http://www.sciencedirect.com/science/article/B6WGF-5207B2F-4/2/d87cd2ae4da00c2b277e2dc79a532c4
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