2,873 research outputs found
Braided Hopf Algebras and Differential Calculus
We show that the algebra of the bicovariant differential calculus on a
quantum group can be understood as a projection of the cross product between a
braided Hopf algebra and the quantum double of the quantum group. The resulting
super-Hopf algebra can be reproduced by extending the exterior derivative to
tensor products.Comment: 8 page
Stable, High-Average-Power, Degenerate Optical Parametric Oscillator at 2.1 ÎĽm
We describe a degenerate 1.064-ÎĽm-pumped pulsed optical parametric oscillator based on MgO:PPLN in compact Littrow-grating cavity configuration, providing 2.7W of average power at 2.1ÎĽm with high spectral and power stability in good spatial beam quality.Peer ReviewedPostprint (author's final draft
Innovation through Design Strategy: Case Study of SMEs in Bandung
The rise of business in the city of Bandung has caused the intensity of competition to be very high. Small-scale businesses are very difficult to survive especially facing companies that have larger economies of scale. Innovation can be one way for SMEs to compete. Previous research stated that implementing a design strategy can trigger opportunities to create innovation in the company. This study examines how design is used by Soca companies to produce innovation as a strategy to survive in competition. Soca is an SME in Bandung that produces glasses with wood materials. As a startup, Soca is considered successful in penetrating the market amid intense competition. This study uses a qualitative method with a descriptive case study approach. Primary data is obtained through document review, in-depth interviews and observations. The results of this study are expected to be a reference for how design strategies are used by SMEs to generate innovation
Keywords Innovations, SMEs, Design Strateg
Noncommutative Harmonic Analysis, Sampling Theory and the Duflo Map in 2+1 Quantum Gravity
We show that the -product for , group Fourier transform and
effective action arising in [1] in an effective theory for the integer spin
Ponzano-Regge quantum gravity model are compatible with the noncommutative
bicovariant differential calculus, quantum group Fourier transform and
noncommutative scalar field theory previously proposed for 2+1 Euclidean
quantum gravity using quantum group methods in [2]. The two are related by a
classicalisation map which we introduce. We show, however, that noncommutative
spacetime has a richer structure which already sees the half-integer spin
information. We argue that the anomalous extra `time' dimension seen in the
noncommutative geometry should be viewed as the renormalisation group flow
visible in the coarse-graining in going from to . Combining our
methods we develop practical tools for noncommutative harmonic analysis for the
model including radial quantum delta-functions and Gaussians, the Duflo map and
elements of `noncommutative sampling theory'. This allows us to understand the
bandwidth limitation in 2+1 quantum gravity arising from the bounded
momentum and to interpret the Duflo map as noncommutative compression. Our
methods also provide a generalised twist operator for the -product.Comment: 53 pages latex, no figures; extended the intro for this final versio
A note on quantization operators on Nichols algebra model for Schubert calculus on Weyl groups
We give a description of the (small) quantum cohomology ring of the flag
variety as a certain commutative subalgebra in the tensor product of the
Nichols algebras. Our main result can be considered as a quantum analog of a
result by Y. Bazlov
Pulse Morphology of the Galactic Center Magnetar PSR J1745-2900
We present results from observations of the Galactic Center magnetar, PSR
J1745-2900, at 2.3 and 8.4 GHz with the NASA Deep Space Network 70 m antenna,
DSS-43. We study the magnetar's radio profile shape, flux density, radio
spectrum, and single pulse behavior over a ~1 year period between MJDs 57233
and 57621. In particular, the magnetar exhibits a significantly negative
average spectral index of = -1.86 0.02 when the
8.4 GHz profile is single-peaked, which flattens considerably when the profile
is double-peaked. We have carried out an analysis of single pulses at 8.4 GHz
on MJD 57479 and find that giant pulses and pulses with multiple emission
components are emitted during a significant number of rotations. The resulting
single pulse flux density distribution is incompatible with a log-normal
distribution. The typical pulse width of the components is ~1.8 ms, and the
prevailing delay time between successive components is ~7.7 ms. Many of the
single pulse emission components show significant frequency structure over
bandwidths of ~100 MHz, which we believe is the first observation of such
behavior from a radio magnetar. We report a characteristic single pulse
broadening timescale of = 6.9 0.2 ms at 8.4 GHz.
We find that the pulse broadening is highly variable between emission
components and cannot be explained by a thin scattering screen at distances
1 kpc. We discuss possible intrinsic and extrinsic mechanisms for the
magnetar's emission and compare our results to other magnetars, high magnetic
field pulsars, and fast radio bursts.Comment: 18 pages, 12 figures, Accepted for publication in ApJ on 2018 August
30. v2: Updated to match published versio
Unlocking the deployment of spectrum sharing with a policy enforcement framework
Spectrum sharing has been proposed as a promising way to increase the efficiency of spectrum usage by allowing incumbent operators (IOs) to share their allocated radio resources with licensee operators (LOs), under a set of agreed rules. The goal is to maximize a common utility, such as the sum rate throughput, while maintaining the level of service required by the IOs. However, this is only guaranteed under the assumption that all “players”respect the agreed sharing rules. In this paper, we propose a comprehensive framework for licensed shared access (LSA) networks that discourages LO misbehavior. Our framework is built around three core functions: misbehavior detection via the employment of a dedicated sensing network; a penalization function; and, a behavior-driven resource allocation. To the best of our knowledge, this is the first time that these components are combined for the monitoring/policing of the spectrum under the LSA framework. Moreover, a novel simulator for LSA is provided as an open access tool, serving the purpose of testing and validating our proposed techniques via a set of extensive system-level simulations in the context of mobile network operators, where IOs and several competing LOs are considered. The results demonstrate that violation of the agreed sharing rules can lead to a great loss of resources for the misbehaving LOs, the amount of which is controlled by the system. Finally, we promote that including a policy enforcement function as part of the spectrum sharing system can be beneficial for the LSA system, since it can guarantee compliance with the spectrum sharing rules and limit the short-term benefits arising from misbehavior
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