15,422 research outputs found
Semiparametric GEE analysis in partially linear single-index models for longitudinal data
In this article, we study a partially linear single-index model for
longitudinal data under a general framework which includes both the sparse and
dense longitudinal data cases. A semiparametric estimation method based on a
combination of the local linear smoothing and generalized estimation equations
(GEE) is introduced to estimate the two parameter vectors as well as the
unknown link function. Under some mild conditions, we derive the asymptotic
properties of the proposed parametric and nonparametric estimators in different
scenarios, from which we find that the convergence rates and asymptotic
variances of the proposed estimators for sparse longitudinal data would be
substantially different from those for dense longitudinal data. We also discuss
the estimation of the covariance (or weight) matrices involved in the
semiparametric GEE method. Furthermore, we provide some numerical studies
including Monte Carlo simulation and an empirical application to illustrate our
methodology and theory.Comment: Published at http://dx.doi.org/10.1214/15-AOS1320 in the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
First R and I Lights and Their Photometric Analyses of GSC 02393-00680
We obtained complete and light curves of GSC 02393-00680 in 2008 and
analyzed them with the 2003 version of the W-D code. It is shown that GSC
02393-00680 is a W-type shallow contact binary system with a high mass ratio
and a degree of contact factor . It will be a good
example to check up on the TRO theory. A period investigation based on all
available data suggests that the system has a small-amplitude period
oscillation (; years). This may indicate it has a
moderate mass close third body, which is similar to XY Leo
Solving the Bars-Green equation for moving mesons in two-dimensional QCD
The two-dimensional QCD in the large limit, generally referred to as the
't Hooft model, is numerically investigated in the axial gauge in a
comprehensive manner. The corresponding Bethe-Salpeter equation for a bound
pair, originally derived by Bars and Green in 1978, was first
numerically tackled by Li and collaborators in late 1980s, yet only for the
{\it stationary} mesons. In this paper, we make further progress by numerically
solving the Bars-Green equation for {\it moving} mesons, ranging from the
chiral pion to charmonium. By choosing several different quark masses, we
computed the corresponding quark condensates, meson spectra and their decay
constants for a variety of meson momenta, and found satisfactory agreement with
their counterparts obtained using light-cone gauge, thus numerically verified
the gauge and Poincar\'{e} invariance of the 't Hooft model. Moreover, we have
explicitly confirmed that, as the meson gets more and more boosted, the large
component of the Bars-Green wave function indeed approaches the corresponding
't Hooft light-cone wave function, while the small component of the wave
function rapidly fades away.Comment: v2, 25 pages, 12 figures, and 1 table; Some figures updated,
references added, typo corrrected; to appear in JHE
Financing Capture Ready Coal-Fired Power Plants in China by Issuing Capture Options
‘Capture Ready’ is a design concept enabling fossil fuel plants to be retrofitted more economically with carbon dioxide capture and storage (CCS) technologies, however financing the cost of capture ready can be problematic, especially in the developing world. We propose that fossil fuel plants issue tradable Capture Options to acquire financing. The Capture Option concept could move CCS forward politically in countries such as China, speed up CCS technology development, help Capture Ready investors diversify risk, and offer global warming investors an alternative investment opportunity. As a detailed case study, we assess the value of a Capture Option and Capture Ready plant for a 600 MW supercritical pulverized coal power plant in China, using a cash flow model with Monte-Carlo simulations. The gross value of Capture Ready varies from CNY3m (84.4m) at an 8% discount rate and the Capture Option is valued at CNY113m (167.3m) for two of the four scenarios analyzed
Behavior Extraction from Examples Using Federate MCMC-Based Particle Filtering
AbstractData-driven methods of simulating a crowd of virtual humans that exhibit behaviors imitating real human crowds play an important role in crowd simulation. In this paper, we propose a Bayesian framework for the extraction of real human's behaviors which exhibit interactions in their daily life using multiple fixed cameras. The described Markov chain Monte Carlo particle filter can effectively deals with interacting targets which are influenced by the proximity and behaviors of other targets. In this paper, we use a Markov random field motion prior combing with a federate filter algorithm which treats the observations discriminatorily to substantially improve the tracking of a fixed number of interacting targets. Simultaneously, we replace the traditional importance sampling step with MCMC sampling step to get over the vast computational requirements for large numbers of targets. i.e., we focus on the data fusion and the behavior recognition process. Finally, experimental results demonstrate that the proposed Bayesian framework deals efficiently and effectively with extractions of interacting behavior
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