Estimation of Extreme Quantiles for Functions of Dependent Random Variables

We propose a new method for estimating the extreme quantiles for a function of several dependent random variables. In contrast to the conventional approach based on extreme value theory, we do not impose the condition that the tail of the underlying distribution admits an approximate parametric form, and, furthermore, our estimation makes use of the full observed data. The proposed method is semiparametric as no parametric forms are assumed on all the marginal distributions. But we select appropriate bivariate copulas to model the joint dependence structure by taking the advantage of the recent development in constructing large dimensional vine copulas. Consequently a sample quantile resulted from a large bootstrap sample drawn from the fitted joint distribution is taken as the estimator for the extreme quantile. This estimator is proved to be consistent. The reliable and robust performance of the proposed method is further illustrated by simulation.Comment: 18 pages, 2 figure

Forecasting the Use of Institutional Elder Care in China: A System Dynamic Simulation

With the rapid population aging in China, the older adults who needs for long-term care (LTC) increased dramatically in the past decades. To forecasting the use of institutional elder care in China, this study constructed a system dynamic model for LTC use to capture the decision-making process of living arrangement and institutional care use among the aging population in China. The results showed that the number of older adults living at institutions will increase from 200 million in 2015 to 290 million in 2035, which account for an increase of 45%. This study provides policy implications that would assist policy makers understand the LTC delivery process and its influence factors, and help implement effective LTC policy scenarios.This work was supported by the National Natural Science Foundation of China (Grant number 71503054)

A key variant in the cis-regulatory element of flowering gene Ghd8 associated with cold tolerance in rice.

Variations in the gene promoter play critical roles in the evolution of important adaptive traits in crops, but direct links of the regulatory mutation to the adaptive change are not well understood. Here, we examine the nucleotide variations in the promoter region of a transcription factor (Ghd8) that control grain number, plant height and heading date in rice. We find that a dominant promoter type of subspecies japonica displayed a high activity for Ghd8 expression in comparison with the one in indica. Transgenic analyses revealed that higher expression levels of Ghd8 delayed heading date and enhanced cold tolerance in rice. Furthermore, a single-nucleotide polymorphism (T1279G) at the position -1279 bp that locates on the potential GA-responsive motif in the Ghd8 promoter affected the expression of this gene. The 1279 T variant has elevated expression of Ghd8, thus conferring increased cold tolerance of rice seedlings. Nucleotide diversity analysis revealed that the approximately 25-kb genomic region surrounding Ghd8 in the subspecies japonica was under significant selection pressure. Our findings demonstrate that the join effects of the regulatory and coding variants largely contribute to the divergence of japonica and indica and increase the adaptability of japonica to the cold environment

Experimental Study on the Bearing Capacity of Glass Deck under the Condition of Vehicle Traffic

In order to study the mechanical properties of the glass plate structure applied to the automobile bridge deck, the bearing capacity test of the glass bridge deck under the wheel load is carried out, and the failure mode, load displacement curve and safety function of the glass plate under the boundary, position and number of layers of the wheel load are analyzed. The results show that the ultimate bearing capacity of laminated glass under the condition of simply supported boundary on both sides is about four sides supported 71.8%. The ultimate bearing capacity of single-layer glass under the boundary condition of simple support on both sides is about four sides 51.4% from the point of view of meeting the structural strength requirements. The loading test is carried out by applying different multiple wheel loads at the plate angle and the center of the plate. The test results can provide reference for the application of the glass bridge deck in engineering

Sensitive frequency-dependence of the carrier-envelope phase effect on bound-bound transition: an interference perspective

We investigate numerically with Hylleraas coordinates the frequency dependence of the carrier-envelope phase (CEP) effect on bound-bound transitions of helium induced by an ultrashort laser pulse of few cycles. We find that the CEP effect is very sensitive to the carrier frequency of the laser pulse, occurring regularly even at far-off resonance frequencies. By analyzing a two-level model, we find that the CEP effect can be attributed to the quantum interference between neighboring multi-photon transition pathways, which is made possible by the broadened spectrum of the ultrashort laser pulse. A general picture is developed along this line to understand the sensitivity of the CEP effect to laser's carrier frequency. Multi-level influence on the CEP effect is also discussed

GumDrop at the DISRPT2019 Shared Task: A Model Stacking Approach to Discourse Unit Segmentation and Connective Detection

In this paper we present GumDrop, Georgetown University's entry at the DISRPT 2019 Shared Task on automatic discourse unit segmentation and connective detection. Our approach relies on model stacking, creating a heterogeneous ensemble of classifiers, which feed into a metalearner for each final task. The system encompasses three trainable component stacks: one for sentence splitting, one for discourse unit segmentation and one for connective detection. The flexibility of each ensemble allows the system to generalize well to datasets of different sizes and with varying levels of homogeneity.Comment: Proceedings of Discourse Relation Parsing and Treebanking (DISRPT2019