1,909 research outputs found
Periodic and homoclinic solutions of the modified 2+1 Chiral model
We use algebraic Backlund transformations (BTs) to construct explicit
solutions of the modified 2+1 chiral model from to SU(n), where
is a 2-torus. Algebraic BTs are parameterized by (poles) and
holomorphic maps from to Gr. We apply B\"acklund
transformations with carefully chosen poles and 's to construct infinitely
many solutions of the 2+1 chiral model that are (i) doubly periodic in space
variables and periodic in time, i.e., triply periodic, (ii) homoclinic in the
sense that the solution has the same stationary limit as and is tangent to a stable linear mode of as and
is tangent to an unstable mode of as .Comment: 17 page
The Impact of Unemployment and Human Development Index on Poverty in Gorontalo Province 2008-2017
This research aims to analyze the impact of unemployment rate and human development index on poverty in Regecies and City in Gorontalo Province. This research uses Panel Data Regression analysis with fixed effect model (FEM). This research uses regional datasets from the Registration Management Information System (SIMREG) and datasets from Central Statistics Bureau (BPS) during 2008-2017. Main findings of this research indicates that (i) unemployment rate has positive but insignificant impact on poverty rate; (ii) human development index has positive and significant impact on poverty rate.
Keywords: Unemployment Rate; Human Development Index (HDI); Poverty
Nematic crossover in BaFeAs under uniaxial stress
Raman scattering can detect spontaneous point-group symmetry breaking without
resorting to single-domain samples. Here we use this technique to study
, the parent compound of the "122" Fe-based
superconductors. We show that an applied compression along the Fe-Fe direction,
which is commonly used to produce untwinned orthorhombic samples, changes the
structural phase transition at temperature into a crossover
that spans a considerable temperature range above . Even in
crystals that are not subject to any applied force, a distribution of
substantial residual stress remains, which may explain phenomena that are
seemingly indicative of symmetry breaking above . Our results
are consistent with an onset of spontaneous nematicity only below
.Comment: 4 pages, 4 figure
Hypergraph-Based Fast Distributed AC Power Flow Optimization
This paper presents a novel distributed approach for solving AC power flow
(PF) problems. The optimization problem is reformulated into a distributed form
using a communication structure corresponding to a hypergraph, by which complex
relationships between subgrids can be expressed as hyperedges. Then, a
hypergraph-based distributed sequential quadratic programming (HDQ) approach is
proposed to handle the reformulated problems, and the hypergraph-based
distributed sequential quadratic programming (HDSQP) is used as the inner
algorithm to solve the corresponding QP subproblems, which are respectively
condensed using Schur complements with respect to coupling variables defined by
hyperedges. Furthermore, we rigorously establish the convergence guarantee of
the proposed algorithm with a locally quadratic rate and the one-step
convergence of the inner algorithm when using the Levenberg-Marquardt
regularization. Our analysis also demonstrates that the computational
complexity of the proposed algorithm is much lower than the state-of-art
distributed algorithm. We implement the proposed algorithm in an open-source
toolbox, i.e., rapidPF, and conduct numerical tests that validate the proof and
demonstrate the great potential of the proposed distributed algorithm in terms
of communication effort and computational speed
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