790 research outputs found
Knowledge Diffusion in R&D Groups: The Impact of Internet Technologies
判型:B5,æ˜å’Œ55å¹´7月12
Meson distribution amplitudes in holographic models
We study the wave functions of light and heavy mesons in both hard-wall (HW)
and soft-wall (SW) holographic models which use AdS/CFT correspondence. In the
case of massless constituents, the asymptotic behaviors of the electromagnetic
form factor, the distribution amplitudes, and the decay constants for the two
models are the same, if the relation between the dilaton scale parameter and
the size of meson is an inverse proportion. On the other hand, by introducing a
quark mass dependence in the wave function, the differences of the distribution
amplitudes between the two models are obvious. In addition, for the SW model,
the dependences of the decay constants of meson on the dilaton scale parameter
differ; especially f_{Qq}\sim \kappa^3/m_Q^2 is consistent with the
prediction of the heavy quark effective theory if \kappa\sim m_Q^{1/2}. Thus
the parameters of the two models are fit by the decay constants of the distinct
mesons; the distribution amplitudes and the \xi-moments are calculated and
compared.Comment: 30 pages, 11 figures, 2 tables, minor modifications and one short
paragraph added, some references added and removed, accepted for publication
in PR
Knowledge Diffusion in R&D Groups: The Impact of Internet Technologies
Knowledge flows are the lifeblood of any R&D organisation. These firms are increasingly
discovering that the knowledge they require is often located beyond their boundaries. In this paper,
we investigate how R&D groups acquire and diffuse external knowledge and the role Internet
technologies play in this process. The focus of our study is on the technological gatekeeper. Previous
studies have found that gatekeepers are key nodes in the innovation process. These sporadic
individuals have the skills to identify useful knowledge outside the firm and disseminate this among
their local colleagues. However, much of the seminal gatekeeper research has been conducted over
two decades ago. In the time since, there have been huge advances in ICT and especially Internet
technologies. These technologies have dramatically altered how knowledge workers source and share
their information. Our objective is to advance the gatekeeper theory into an era where the knowledge
worker is saturated with information. Using case study methods, we examine knowledge flows in the
R&D group of an Irish medical devices firm. Our results indicate that due to advances in Internet
technology, the traditional gatekeeper no longer exists to any great extent. Instead, the modern R&D
lab acquires and diffuses external knowledge through a combination of a ‘web gatekeeper’ and a
‘knowledge transformer.
Social capital in distributed system development: A case of grid development in particle physics
No organisation, no matter how large, can remain totally reliant on the stocks of new knowledge it
generates itself. In order to keep abreast of the latest scientific and technological developments, R&D
organisations must continuously import knowledge from beyond the organisations boundaries. How
does this external knowledge which is critical to success then become absorbed and integrated into the
firm? Our paper addresses this question through the lens of the influential technological gatekeeper
theory. Drawing on social network analysis (SNA) and interview evidence from a medical devices
R&D group, we find that the gatekeeper role is still vital, but no longer needs to be performed by a
single individual. Instead, the modern R&D group can keep abreast of the latest technological
advances through a combination of Web-enabled internal and external communication specialists. A
unique contribution this paper makes to the IT-enable social network literature is the development of
an updated conceptual framework of how the gatekeeper role is performed in the modern R&D group
How Are Curiosity and Interest Different? Naive Bayes Classification of People's Beliefs
Researchers studying curiosity and interest note a lack of consensus in whether and how these important motivations for learning are distinct. Empirical attempts to distinguish them are impeded by this lack of conceptual clarity. Following a recent proposal that curiosity and interest are folk concepts, we sought to determine a non-expert consensus view on their distinction using machine learning methods. In Study 1, we demonstrate that there is a consensus in how they are distinguished, by training a Naïve Bayes classification algorithm to distinguish between free-text definitions of curiosity and interest (n = 396 definitions) and using cross-validation to test the classifier on two sets of data (main n = 196; additional n = 218). In Study 2, we demonstrate that the non-expert consensus is shared by experts and can plausibly underscore future empirical work, as the classifier accurately distinguished definitions provided by experts who study curiosity and interest (n = 92). Our results suggest a shared consensus on the distinction between curiosity and interest, providing a basis for much-needed conceptual clarity facilitating future empirical work. This consensus distinguishes curiosity as more active information seeking directed towards specific and previously unknown information. In contrast, interest is more pleasurable, in-depth, less momentary information seeking towards information in domains where people already have knowledge. However, we note that there are similarities between the concepts, as they are both motivating, involve feelings of wanting, and relate to knowledge acquisition
The Role of Domain Satisfaction in Explaining the Paradoxical Association Between Life Satisfaction and Age
Although aging is associated with declines in many life circumstances, overall life satisfaction does not appear to sharply decline with age. One explanation for this paradoxical finding is that several life domains improve with age such that increases in certain domains balance the decreases in others. Life and domain satisfaction data from eight years of the British Household Panel Study were analyzed to evaluate this hypothesis. Results showed that although domain satisfaction scores demonstrate distinct trajectories, the aggregate of these distinct trajectories resembled the overall life satisfaction trajectory. These findings have implications for top-down and bottom-up models of life satisfaction
Navy composite maintenance and repair experience
The Navy has been a strong proponent of composites for aircraft structure. Fleet use of composites started with the F-14 in the early 1970's and has steadily increased. This experience base provides sufficient information to allow an evaluation of the maintenance performance of polymer composites in service. A summary is presented of the Navy's experience with maintenance of composite structure. The general types of damage experienced in the fleet as well as specific examples of composite damage to aircraft is described. The impact of future designs on supportability is also discussed
Simplex GPS and InSAR Inversion Software
Changes in the shape of the Earth's surface can be routinely measured with precisions better than centimeters. Processes below the surface often drive these changes and as a result, investigators require models with inversion methods to characterize the sources. Simplex inverts any combination of GPS (global positioning system), UAVSAR (uninhabited aerial vehicle synthetic aperture radar), and InSAR (interferometric synthetic aperture radar) data simultaneously for elastic response from fault and fluid motions. It can be used to solve for multiple faults and parameters, all of which can be specified or allowed to vary. The software can be used to study long-term tectonic motions and the faults responsible for those motions, or can be used to invert for co-seismic slip from earthquakes. Solutions involving estimation of fault motion and changes in fluid reservoirs such as magma or water are possible. Any arbitrary number of faults or parameters can be considered. Simplex specifically solves for any of location, geometry, fault slip, and expansion/contraction of a single or multiple faults. It inverts GPS and InSAR data for elastic dislocations in a half-space. Slip parameters include strike slip, dip slip, and tensile dislocations. It includes a map interface for both setting up the models and viewing the results. Results, including faults, and observed, computed, and residual displacements, are output in text format, a map interface, and can be exported to KML. The software interfaces with the QuakeTables database allowing a user to select existing fault parameters or data. Simplex can be accessed through the QuakeSim portal graphical user interface or run from a UNIX command line
- …