403 research outputs found
Understanding the Business Value: Towards a Taxonomy of Industrial Use Scenarios enabled by Cyber-Physical Systems in the Equipment Manufacturing Industry
The trend of digitalization provides new opportunities for industrial equipment manufactures as sensor technology and ubiquitous connectivity become part of the equipment. In particular, cyber-physical systems (CPSs) enable digital innovation for the industrial product and service business by improving operational efficiencies, facilitating innovative hybrid business models, and fuelling servitization in manufacturing. Despite the new opportunities, so far no research has been conducted to investigate and classify configurations and affordances of this new technology. To gain both a broad and in-depth understanding of use scenarios and added-value of CPSs for the service business in the equipment industry, a multi-method approach is chosen: a systematic literature review as well as case study research are conducted. Grounded in existing literature and based on empirical data of 45 use scenarios, we propose a taxonomy to classify use scenarios enabled by CPSs in the equipment industry. This work contributes to the theoretical body of knowledge by proposing a taxonomy of use scenarios enabled by CPSs. The taxonomy can be (1) leveraged to categorize use scenarios of CPSs in the equipment manufacturing industry and (2) used as a framework for further research. Practitioners can use the taxonomy to classify and compare use scenarios as well as identify business model archetypes
Second Order Power Corrections in the Heavy Quark Effective Theory I. Formalism and Meson Form Factors
In the heavy quark effective theory, hadronic matrix elements of currents
between two hadrons containing a heavy quark are expanded in inverse powers of
the heavy quark masses, with coefficients that are functions of the kinematic
variable . For the ground state pseudoscalar and vector mesons, this
expansion is constructed at order . A minimal set of universal form
factors is defined in terms of matrix elements of higher dimension operators in
the effective theory. The zero recoil normalization conditions following from
vector current conservation are derived. Several phenomenological applications
of the general results are discussed in detail. It is argued that at zero
recoil the semileptonic decay rates for and receive only small second order corrections, which are unlikely
to exceed the level of a few percent. This supports the usefulness of the heavy
quark expansion for a reliable determination of .Comment: (34 pages, REVTEX, two postscript figures available upon request),
SLAC-PUB-589
Two-loop corrections to the Isgur-Wise function in QCD sum rules
We complete the QCD sum rule analysis of the Isgur Wise form factor
at next-to-leading order in renormalization-group improved
perturbation theory. To this end, the exact result for the two-loop corrections
to the perturbative contribution is derived using the heavy quark effective
theory. Several techniques for the evaluation of two-loop integrals involving
two different types of heavy quark propagators are discussed in detail, among
them the methods of integration by parts and differential equations. The
order- corrections to the Isgur-Wise function turn out to be small
and well under control. At large recoil, they tend to decrease the form factor
by .Comment: 24 pages (REVTEX), 2 figures available upon request, SLAC-PUB-599
The anomalous threshold, confinement, and an essential singularity in the heavy-light form factor
The analytic behavior of the heavy-light meson form factor is investigated
using several relativistic examples including unconfined, weakly confined, and
strongly confined mesons. It is observed that confinement erases the anomalous
threshold singularity and also induces an essential singularity at the normal
annihilation threshold. In the weak confinement limit, the "would be" anomalous
threshold contribution is identical to that of the real singularity on its
space-like side.Comment: Latex 2.09 with epsf.sty. 24 pages of text and 8 postscript figures.
Postscript version of complete paper will also be available soon at
http://phenom.physics.wisc.edu/pub/preprints/1997/madph-97-983 or at
ftp://phenom.physics.wisc.edu/pub/preprints/1997/madph-97-98
QCD-Based Interpretation of the Lepton Spectrum in Inclusive Decays
We present a QCD-based approach to the endpoint region of the lepton spectrum
in decays. We introduce a genuinely
nonperturbative form factor, the shape function, which describes the fall-off
of the spectrum close to the endpoint. The moments of this function are related
to forward scattering matrix elements of local, higher-dimension operators. We
find that nonperturbative effects are dominant over a finite region in the
lepton energy spectrum, the width of which is related to the kinetic energy of
the -quark inside the meson. Applications of our method to the
extraction of fundamental standard model parameters, among them , are
discussed in detail.Comment: 17 pages LaTeX, 3 post- script figures available upon request,
CERN-TH.7087/9
Subleading Shape Functions in Inclusive B Decays
The contributions of subleading shape functions to inclusive decay
distributions of B mesons are derived from a systematic two-step matching of
QCD current correlators onto soft-collinear and heavy-quark effective theory.
At tree-level, the results can be expressed in terms of forward matrix elements
of bi-local light-cone operators. Four-quark operators, which arise at O(g^2),
are included. Their effects can be absorbed entirely into a redefinition of
other shape functions. Our results are in disagreement with some previous
studies of subleading shape-function effects in the literature. A numerical
analysis of B->X_u+l+nu decay distributions suggests that power corrections are
small, with the possible exception of the endpoint region of the charged-lepton
energy spectrum.Comment: 22 pages, 2 figures; several typos corrected; version published in
JHE
Green-to-red photoconvertible fluorescent proteins: tracking cell and protein dynamics on standard wide-field mercury arc-based microscopes
<p>Abstract</p> <p>Background</p> <p>Green fluorescent protein (GFP) and other FP fusions have been extensively utilized to track protein dynamics in living cells. Recently, development of photoactivatable, photoswitchable and photoconvertible fluorescent proteins (PAFPs) has made it possible to investigate the fate of discrete subpopulations of tagged proteins. Initial limitations to their use (due to their tetrameric nature) were overcome when monomeric variants, such as Dendra, mEos, and mKikGR were cloned/engineered.</p> <p>Results</p> <p>Here, we report that by closing the field diaphragm, selective, precise and irreversible green-to-red photoconversion (330-380 nm illumination) of discrete subcellular protein pools was achieved on a wide-field fluorescence microscope equipped with standard DAPI, Fluorescein, and Rhodamine filter sets and mercury arc illumination within 5-10 seconds. Use of a DAPI-filter cube with long-pass emission filter (LP420) allowed the observation and control of the photoconversion process in real time. Following photoconversion, living cells were imaged for up to 5 hours often without detectable phototoxicity or photobleaching.</p> <p>Conclusions</p> <p>We demonstrate the practicability of this technique using Dendra2 and mEos2 as monomeric, photoconvertible PAFP representatives fused to proteins with low (histone H2B), medium (gap junction channel protein connexin 43), and high (α-tubulin; clathrin light chain) dynamic cellular mobility as examples. Comparable efficient, irreversible green-to-red photoconversion of selected portions of cell nuclei, gap junctions, microtubules and clathrin-coated vesicles was achieved. Tracking over time allowed elucidation of the dynamic live-cycle of these subcellular structures. The advantage of this technique is that it can be performed on a standard, relatively inexpensive wide-field fluorescence microscope with mercury arc illumination. Together with previously described laser scanning confocal microscope-based photoconversion methods, this technique promises to further increase the general usability of photoconvertible PAFPs to track the dynamic movement of cells and proteins over time.</p
The Subleading Isgur-Wise Form Factor to Order in QCD Sum Rules
We calculate the contributions arising at order in the QCD sum
rule for the spin-symmetry violating universal function ,
which appears at order in the heavy quark expansion of meson form
factors. In particular, we derive the two-loop perturbative contribution to the
sum rule. Over the kinematic range accessible in
decays, we find that does not exceed the level of , indicating that power corrections induced by the chromo-magnetic operator
in the heavy quark expansion are small.Comment: 12 pages ReVTeX, 3 figures available upon request, SLAC-PUB-6017,
WIS-92/99/Dec-P
Specifications of standards in systems and synthetic biology: Status and developments in 2020
This special issue of the Journal of Integrative Bioinformatics presents papers related to the 10th COMBINE meeting together with the annual update of COMBINE standards in systems and synthetic biology
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