16,637 research outputs found
What Inspires Leisure Time Invention?
This paper seeks to understand the intriguing but only sparsely explored phenomenon of “leisure time invention,” where the main underlying idea for the new product or process occurs when the inventor is away from the workplace. We add to previous research by focussing on the inventive creativity of the individual researcher, and reassessing the image of researchers inventing during unpaid time – who have often been dispatched as “hobbyists”. Based on the responses from a survey of over 3,000 German inventors, we tested hypotheses on the conditions under which leisure time invention is likely to arise. Results suggest that the incidence of leisure time invention is positively related to exposure to a variety of knowledge inputs – but, surprisingly, not to the quality of prior inventive output. Leisure time inventions are more frequently observed in conceptual-based technologies than in science-based technologies, in smaller R&D projects, and in externally financed R&D projects
What Inspires Leisure Time Invention?
This paper seeks to understand the intriguing but only sparsely explored phenomenon of “leisure time invention,” where the main underlying idea for the new product or process occurs when the inventor is away from the workplace. We add to previous research by focussing on the inventive creativity of the individual researcher, and reassessing the image of researchers inventing during unpaid time – who have often been dispatched as “hobbyists”. Based on the responses from a survey of over 3,000 German inventors, we tested hypotheses on the conditions under which leisure time invention is likely to arise. Results suggest that the incidence of leisure time invention is positively related to exposure to a variety of knowledge inputs – but, surprisingly, not to the quality of prior inventive output. Leisure time inventions are more frequently observed in conceptual-based technologies than in science-based technologies, in smaller R&D projects, and in externally financed R&D projects.Leisure Time; Inventiveness; Organizational Creativity
Chiral primary one-point functions in the D3-D7 defect conformal field theory
JHEP is an open-access journal funded by SCOAP3 and licensed under CC BY 4.0archiveprefix: arXiv primaryclass: hep-th reportnumber: NORDITA-2012-81 slaccitation: %%CITATION = ARXIV:1210.7015;%%archiveprefix: arXiv primaryclass: hep-th reportnumber: NORDITA-2012-81 slaccitation: %%CITATION = ARXIV:1210.7015;%%C.F.K. and D.Y. were supported in part by FNU through grant number 272-08-0329.
G.W.S. is supported by NSERC of Canada and by the Villum foundation through their
Velux Visiting Professor program
High frequency sound in superfluid 3He-B
We present measurements of the absolute phase velocity of transverse and
longitudinal sound in superfluid 3He-B at low temperature, extending from the
imaginary squashing mode to near pair-breaking. Changes in the transverse phase
velocity near pair-breaking have been explained in terms of an order parameter
collective mode that arises from f-wave pairing interactions, the so-called
J=4- mode. Using these measurements, we establish lower bounds on the energy
gap in the B-phase. Measurement of attenuation of longitudinal sound at low
temperature and energies far above the pair-breaking threshold, are in
agreement with the lower bounds set on pair-breaking. Finally, we discuss our
estimations for the strength of the f-wave pairing interactions and the Fermi
liquid parameter, F4s.Comment: 15 pages, 8 figures, accepted to J. Low Temp. Phy
Tensile Cervical Facet Capsule Ligament Mechanics: Failure and Subfailure Responses in the Rat
Clinical, epidemiological, and biomechanical studies suggest the involvement of the cervical facet joint in neck pain. Mechanical studies have suggested the facet capsular ligament to be at risk for subfailure tensile injury during whiplash kinematics of the neck. Ligament mechanical properties can be altered by subfailure injury and such loading can induce cellular damage. However, at present, there is no clear understanding of the physiologic context of subfailure facet capsular ligament injury and mechanical implications for whiplash-related pain. Therefore, this study aimed to define a relationship between mechanical properties at failure and a subfailure condition associated with pain for tension in the rat cervical facet capsular ligament. Tensile failure studies of the C6/C7 rat cervical facet capsular ligament were performed using a customized vertebral distraction device. Force and displacement at failure were measured and stiffness and energy to failure were calculated. Vertebral motions and ligament deformations were tracked and maximum principal strains and their directions were calculated. Mean tensile force at failure (2.96±0.69 N) was significantly greater (p\u3c0.005) than force at subfailure (1.17±0.48 N). Mean ligament stiffness to failure was 0.75±0.27 N/mm. Maximum principal strain at failure (41.3±20.0%) was significantly higher (p=0.003) than the corresponding subfailure value (23.1±9.3%). This study determined that failure and a subfailure painful condition were significantly different in ligament mechanics and findings provide preliminary insight into the relationship between mechanics and pain physiology for this ligament. Together with existing studies, these findings offer additional considerations for defining mechanical thresholds for painful injuries
Vortex Dynamics in Self-Dual Chern-Simons Higgs Systems
We consider vortex dynamics in self-dual Chern-Simons Higgs systems. We show
that the naive Aharanov-Bohm phase is the inverse of the statistical phase
expected from the vortex spin, and that the self-dual configurations of
vortices are degenerate in energy but not in angular momentum. We also use the
path integral formalism to derive the dual formulation of Chern-Simons Higgs
systems in which vortices appear as charged particles. We argue that besides
the electromagnetic interaction, there is an additional interaction between
vortices, the so-called Magnus force, and that these forces can be put together
into a single `dual electromagnetic' interaction. This dual electromagnetic
interaction leads to the right Aharanov-Bohm phase. We also derive and study
the effective action for slowly moving vortices, which contains terms both
linear and quadratic in the vortex velocity.Comment: 36 pages and three figures (available under request), Columbia and
CERN preprin
Effect of in-plane magnetic field on the photoluminescence spectrum of modulation-doped quantum wells and heterojunctions
The photoluminescence (PL) spectrum of modulation-doped GaAs/AlGaAs quantum
wells (MDQW) and heterojunctions (HJ) is studied under a magnetic field
() applied parallel to the two-dimensional electron gas (2DEG) layer.
The effect of strongly depends on the electron-hole separation
(), and we revealed remarkable -induced modifications of the PL
spectra in both types of heterostructures. A model considering the direct
optical transitions between the conduction and valence subband that are shifted
in k-space under , accounts qualitatively for the observed spectral
modifications. In the HJs, the PL intensity of the bulk excitons is strongly
reduced relatively to that of the 2DEG with increasing . This means
that the distance between the photoholes and the 2DEG decreases with increased
, and that free holes are responsible for the hole-2DEG PL.Comment: 6pages, 5figure
Bose-Einstein Condensation of Atoms in a Trap
We point out that the local density approximation (LDA) of Oliva is an
adaptation of the Thomas-Fermi method, and is a good approximation when
,
the LDA leads to a quantitative result (14') easily checked by experiments.
Critical remarks are made about the physics of the many body problem in terms
of the scattering length .Comment: 9 pages, latex. one figure, available from author
Holographic DC conductivities from the open string metric
We study the DC conductivities of various holographic models using the open
string metric (OSM), which is an effective metric geometrizing density and
electromagnetic field effect. We propose a new way to compute the nonlinear
conductivity using OSM. As far as the final conductivity formula is concerned,
it is equivalent to the Karch-O'Bannon's real-action method. However, it yields
a geometrical insight and technical simplifications. Especially, a real-action
condition is interpreted as a regular geometry condition of OSM. As
applications of the OSM method, we study several holographic models on the
quantum Hall effect and strange metal. By comparing a Lifshitz background and
the Light-Cone AdS, we show how an extra parameter can change the temperature
scaling behavior of conductivity. Finally we discuss how OSM can be used to
study other transport coefficients, such as diffusion constant, and effective
temperature induced by the effective world volume horizon.Comment: 33 page
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