5,242 research outputs found
Growth and Trade Horizons for Asia: Long Term Forecasts for Regional Integration
Economic emergence of the People?s Republic of China (PRC) and India has fundamentally altered the economic landscape of Asia and its relation to the global economy. Using the new dynamic global model, we present forecasts for Asian expansion over 2025. These baseline growth forecasts elucidate shifting patterns of regional specialization and their consequences for growth and structural change in the Asian economies. The central role of trade is examined through analysis of a variety of hypothetical global and regional trade agreements. Our results indicate that trade within the Asian region is far from reaching its potential, and policies that facilitate integration and more efficient regional trade can accelerate growth, especially for lower-income Asia. A deeper and more inclusive Asian free trade area can achieve for its members large benefits. As an emerging growth bridge between the PRC and India, ASEAN economies have the most to gain from Asian economic integration.globalization, integration, Asia
Contingency-Constrained Unit Commitment with Post-Contingency Corrective Recourse
We consider the problem of minimizing costs in the generation unit commitment
problem, a cornerstone in electric power system operations, while enforcing an
N-k-e reliability criterion. This reliability criterion is a generalization of
the well-known - criterion, and dictates that at least
fraction of the total system demand must be met following the failures of
or fewer system components. We refer to this problem as the
Contingency-Constrained Unit Commitment problem, or CCUC. We present a
mixed-integer programming formulation of the CCUC that accounts for both
transmission and generation element failures. We propose novel cutting plane
algorithms that avoid the need to explicitly consider an exponential number of
contingencies. Computational studies are performed on several IEEE test systems
and a simplified model of the Western US interconnection network, which
demonstrate the effectiveness of our proposed methods relative to current
state-of-the-art
Contingency-Constrained Unit Commitment With Intervening Time for System Adjustments
The N-1-1 contingency criterion considers the con- secutive loss of two
components in a power system, with intervening time for system adjustments. In
this paper, we consider the problem of optimizing generation unit commitment
(UC) while ensuring N-1-1 security. Due to the coupling of time periods
associated with consecutive component losses, the resulting problem is a very
large-scale mixed-integer linear optimization model. For efficient solution, we
introduce a novel branch-and-cut algorithm using a temporally decomposed
bilevel separation oracle. The model and algorithm are assessed using multiple
IEEE test systems, and a comprehensive analysis is performed to compare system
performances across different contingency criteria. Computational results
demonstrate the value of considering intervening time for system adjustments in
terms of total cost and system robustness.Comment: 8 pages, 5 figure
Non Parametric Instrumental Regression
The focus of the paper is the nonparametric estimation of an instrumental regression function ϕ defined by conditional moment restrictions stemming from a structural econometric model: E [Y − ϕ (Z) | W] = 0, and involving endogenous variables Y and Z and instruments W . The function ϕ is the solution of an ill-posed inverse problem and we propose an estimation procedure based on Tikhonov regularization. The paper analyses identification and overidentification of this model and presents asymptotic properties of the estimated nonparametric instrumental regression function.
Thermal and electronic transport characteristics of highly stretchable graphene kirigami
For centuries, cutting and folding the papers with special patterns have been
used to build beautiful, flexible and complex three-dimensional structures.
Inspired by the old idea of kirigami (paper cutting), and the outstanding
properties of graphene, recently graphene kirigami structures were fabricated
to enhance the stretchability of graphene. However, the possibility of further
tuning the electronic and thermal transport along the 2D kirigami structures
have remained original to investigate. We therefore performed extensive
atomistic simulations to explore the electronic, heat and load transfer along
various graphene kirigami structures. The mechanical response and thermal
transport were explored using classical molecular dynamics simulations. We then
used a real-space Kubo-Greenwood formalism to investigate the charge transport
characteristics in graphene kirigami. Our results reveal that graphene kirigami
structures present highly anisotropic thermal and electrical transport.
Interestingly, we show the possibility of tuning the thermal conductivity of
graphene by four orders of magnitude. Moreover, we discuss the engineering of
kirigami patterns to further enhance their stretchability by more than 10 times
as compared with pristine graphene. Our study not only provides a general
understanding concerning the engineering of electronic, thermal and mechanical
response of graphene but more importantly can be useful to guide future studies
with respect to the synthesis of other 2D material kirigami structures, to
reach highly flexible and stretchable nanostructures with finely tunable
electronic and thermal properties.Comment: 29 pages, 9 figures, 1 supplementary figur
Mass-concentration relation of clusters of galaxies from CFHTLenS
Based on weak lensing data from the Canada-France-Hawaii Telescope Lensing
Survey (CFHTLenS), in this paper we study the mass-concentration (-)
relation for redMaPPer clusters in the fields. We extract the
- relation by measuring the density profiles of individual clusters
instead of using stacked weak lensing signals. By performing Monte Carlo
simulations, we demonstrate that although the signal-to-noise ratio for each
individual cluster is low, the unbiased - relation can still be reliably
derived from a large sample of clusters by carefully taking into account the
impacts of shape noise, cluster center offset, dilution effect from member or
foreground galaxies, and the projection effect. Our results show that within
error bars the derived - relation for redMaPPer clusters is in agreement
with simulation predictions. There is a weak deviation in that the halo
concentrations calibrated by Monte Carlo simulations are somewhat higher than
that predicted from cosmology.Comment: Accepted for Publication in ApJ. 18 pages, 8 figures. Updated to
match the published versio
Doubly resonant second-harmonic generation of a vortex beam from a bound state in the continuum
Second harmonic generation in nonlinear materials can be greatly enhanced by
realizing doubly-resonant cavities with high quality factors. However,
fulfilling such doubly resonant condition in photonic crystal (PhC) cavities is
a long-standing challenge, because of the difficulty in engineering photonic
bandgaps around both frequencies. Here, by implementing a second-harmonic bound
state in the continuum (BIC) and confining it with a heterostructure design, we
show the first doubly-resonant PhC slab cavity with W
conversion efficiency under continuous wave excitation. We also report the
confirmation of highly normal-direction concentrated far-field emission pattern
with radial polarization at the second harmonic frequency. These results
represent a solid verification of previous theoretical predictions and a
cornerstone achievement, not only for nonlinear frequency conversion but also
for vortex beam generation and prospective nonclassical sources of radiation.Comment: revtex4-2, 7 pages, 5 figures, conference CLE
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