163,884 research outputs found
Buck-boost dc voltage regulator
Circuit provides voltage regulation through a wide range of operating frequencies without intervals of high power dissipation
Organized social complexity as an analytical problem - An introduction and explication
Systems analysis of organized social complexity in terms of independent variable
Enabling activities, professionals' experience and resource relationships - The efficacy of entrepreneurial and bootlegging activities
Role of contemporary professional in organization
Binary forms as sums of two squares and Ch\^atelet surfaces
The representation of integral binary forms as sums of two squares is
discussed and applied to establish the Manin conjecture for certain Ch\^atelet
surfaces defined over the rationals.Comment: 33 page
Sums of arithmetic functions over values of binary forms
Given a suitable arithmetic function h, we investigate the average order of h
as it ranges over the values taken by an integral binary form F. A general
upper bound is obtained for this quantity, in which the dependence upon the
coefficients of F is made completely explicit.Comment: 12 page
Fast network configuration in Software Defined Networking
Software Defined Networking (SDN) provides a framework to dynamically adjust and re-program the data plane with the use of flow rules. The realization of highly adaptive SDNs with the ability to respond to changing demands or recover after a network failure in a short period of time, hinges on efficient updates of flow rules. We model the time to deploy a set of flow rules by the update time at the bottleneck switch, and formulate the problem of selecting paths to minimize the deployment time under feasibility constraints as a mixed integer linear program (MILP). To reduce the computation time of determining flow rules, we propose efficient heuristics designed to approximate the minimum-deployment-time solution by relaxing the MILP or selecting the paths sequentially. Through extensive simulations we show that our algorithms outperform current, shortest path based solutions by reducing the total network configuration time up to 55% while having similar packet loss, in the considered scenarios. We also demonstrate that in a networked environment with a certain fraction of failed links, our algorithms are able to reduce the average time to reestablish disrupted flows by 40%
Simulation of the hydrogen ground state in Stochastic Electrodynamics
Stochastic electrodynamics is a classical theory which assumes that the
physical vacuum consists of classical stochastic fields with average energy
in each mode, i.e., the zero-point Planck spectrum.
While this classical theory explains many quantum phenomena related to harmonic
oscillator problems, hard results on nonlinear systems are still lacking. In
this work the hydrogen ground state is studied by numerically solving the
Abraham -- Lorentz equation in the dipole approximation. First the stochastic
Gaussian field is represented by a sum over Gaussian frequency components, next
the dynamics is solved numerically using OpenCL. The approach improves on work
by Cole and Zou 2003 by treating the full problem and reaching longer
simulation times. The results are compared with a conjecture for the ground
state phase space density. Though short time results suggest a trend towards
confirmation, in all attempted modelings the atom ionises at longer times.Comment: 20 pages, 9 figures. Published version, minor change
- …