1,333 research outputs found
Web API Fragility: How Robust is Your Web API Client
Web APIs provide a systematic and extensible approach for
application-to-application interaction. A large number of mobile applications
makes use of web APIs to integrate services into apps. Each Web API's evolution
pace is determined by their respective developer and mobile application
developers are forced to accompany the API providers in their software
evolution tasks. In this paper we investigate whether mobile application
developers understand and how they deal with the added distress of web APIs
evolving. In particular, we studied how robust 48 high profile mobile
applications are when dealing with mutated web API responses. Additionally, we
interviewed three mobile application developers to better understand their
choices and trade-offs regarding web API integration.Comment: Technical repor
Electromechanically induced absorption in a circuit nano-electromechanical system
A detailed analysis of electromechanically induced absorption (EMIA) in a
circuit nano-electromechanical hybrid system consisting of a superconducting
microwave resonator coupled to a nanomechanical beam is presented. By
performing two-tone spectroscopy experiments we have studied EMIA as a function
of the drive power over a wide range of drive and probe tone detunings. We find
good quantitative agreement between experiment and theoretical modeling based
on the Hamiltonian formulation of a generic electromechanical system. We show
that the absorption of microwave signals in an extremely narrow frequency band
(\Delta\omega/2\pi <5 Hz) around the cavity resonance of about 6 GHz can be
adjusted over a range of more than 25 dB on varying the drive tone power by a
factor of two. Possible applications of this phenomenon include notch filters
to cut out extremely narrow frequency bands (< Hz) of a much broader band of
the order of MHz defined by the resonance width of the microwave cavity. The
amount of absorption as well as the filtered frequency is tunable over the full
width of the microwave resonance by adjusting the power and frequency of the
drive field. At high drive power we observe parametric microwave amplification
with the nanomechanical resonator. Due to the very low loss rate of the
nanomechanical beam the drive power range for parametric amplification is
narrow, since the beam rapidly starts to perform self-oscillations.Comment: 16 pages, 5 figure
Continuous phase transitions with a convex dip in the microcanonical entropy
The appearance of a convex dip in the microcanonical entropy of finite
systems usually signals a first order transition. However, a convex dip also
shows up in some systems with a continuous transition as for example in the
Baxter-Wu model and in the four-state Potts model in two dimensions. We
demonstrate that the appearance of a convex dip in those cases can be traced
back to a finite-size effect. The properties of the dip are markedly different
from those associated with a first order transition and can be understood
within a microcanonical finite-size scaling theory for continuous phase
transitions. Results obtained from numerical simulations corroborate the
predictions of the scaling theory.Comment: 8 pages, 7 figures, to appear in Phys. Rev.
Determination of effective mechanical properties of a double-layer beam by means of a nano-electromechanical transducer
We investigate the mechanical properties of a doubly-clamped, double-layer
nanobeam embedded into an electromechanical system. The nanobeam consists of a
highly pre-stressed silicon nitride and a superconducting niobium layer. By
measuring the mechanical displacement spectral density both in the linear and
the nonlinear Duffing regime, we determine the pre-stress and the effective
Young's modulus of the nanobeam. An analytical double-layer model
quantitatively corroborates the measured values. This suggests that this model
can be used to design mechanical multilayer systems for electro- and
optomechanical devices, including materials controllable by external parameters
such as piezoelectric, magnetrostrictive, or in more general multiferroic
materials.Comment: 4 pages, 4 figures, 1 supplemental materia
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