9,893 research outputs found
Optimal design of pipes in series: An explicit approximation
This paper introduces a new methodology for the optimum design of pipes in series, named Optimum Hydraulic Grade Line (OHGL). This methodology is explicit and is based on the knowledge of the series topology and the geometrical distribution of water demands on nodes, i.e. the way in which the pipe in series delivers water mass as function of the distance from the entrance. OHGL consists in the pre-determination of that hydraulic grade line which gives the minimum construction cost, in an explicit way. Once this line has been established, calculation of the pipe’s continuous diameters is direct; after a round up to commercial diameters is developed. To validate the proposed methodology, several pipes in series were designed both using GA and OHGL. Four hundred series were used in total, each with different topological characteristics and demands. Keywords: Pipe in series, optimum design, genetic algorithms, optimum hydraulic grade line
A computational approach to the Thompson group
Let denote the Thompson group with standard generators , .
It is a long standing open problem whether is an amenable group. By a
result of Kesten from 1959, amenability of is equivalent to and to where in both
cases the norm of an element in the group ring is computed in
via the regular representation of . By extensive numerical
computations, we obtain precise lower bounds for the norms in and ,
as well as good estimates of the spectral distributions of
and of with respect to the tracial state on the
group von Neumann Algebra . Our computational results suggest, that
It is
however hard to obtain precise upper bounds for the norms, and our methods
cannot be used to prove non-amenability of .Comment: appears in International Journal of Algebra and Computation (2015
Circuit Quantum Electrodynamics with a Superconducting Quantum Point Contact
We consider a superconducting quantum point contact in a circuit quantum
electrodynamics setup. We study three different configurations, attainable with
current technology, where a quantum point contact is coupled galvanically to a
coplanar waveguide resonator. Furthermore, we demonstrate that the strong and
ultrastrong coupling regimes can be achieved with realistic parameters,
allowing the coherent exchange between a superconducting quantum point contact
and a quantized intracavity field.Comment: 5 pages, 4 figures. Updated version, accepted for publication as a
Rapid Communication in Physical Review
Parity-dependent State Engineering and Tomography in the ultrastrong coupling regime
Reaching the strong coupling regime of light-matter interaction has led to an
impressive development in fundamental quantum physics and applications to
quantum information processing. Latests advances in different quantum
technologies, like superconducting circuits or semiconductor quantum wells,
show that the ultrastrong coupling regime (USC) can also be achieved, where
novel physical phenomena and potential computational benefits have been
predicted. Nevertheless, the lack of effective decoupling mechanism in this
regime has so far hindered control and measurement processes. Here, we propose
a method based on parity symmetry conservation that allows for the generation
and reconstruction of arbitrary states in the ultrastrong coupling regime of
light-matter interactions. Our protocol requires minimal external resources by
making use of the coupling between the USC system and an ancillary two-level
quantum system.Comment: Improved version. 9 pages, 5 figure
Quantum Simulations of Relativistic Quantum Physics in Circuit QED
We present a scheme for simulating relativistic quantum physics in circuit
quantum electrodynamics. By using three classical microwave drives, we show
that a superconducting qubit strongly-coupled to a resonator field mode can be
used to simulate the dynamics of the Dirac equation and Klein paradox in all
regimes. Using the same setup we also propose the implementation of the
Foldy-Wouthuysen canonical transformation, after which the time derivative of
the position operator becomes a constant of the motion.Comment: 13 pages, 3 figure
- …