41 research outputs found
Cram\'{e}r-type moderate deviations for Studentized two-sample -statistics with applications
Two-sample -statistics are widely used in a broad range of applications,
including those in the fields of biostatistics and econometrics. In this paper,
we establish sharp Cram\'{e}r-type moderate deviation theorems for Studentized
two-sample -statistics in a general framework, including the two-sample
-statistic and Studentized Mann-Whitney test statistic as prototypical
examples. In particular, a refined moderate deviation theorem with second-order
accuracy is established for the two-sample -statistic. These results extend
the applicability of the existing statistical methodologies from the one-sample
-statistic to more general nonlinear statistics. Applications to two-sample
large-scale multiple testing problems with false discovery rate control and the
regularized bootstrap method are also discussed.Comment: Published at http://dx.doi.org/10.1214/15-AOS1375 in the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Magnetic properties of Er-doped ZnO films prepared by reactive magnetron sputtering
All Zn1−x
Er
x
O (x=0.04, 0.05, and 0.17) films deposited on glass substrates by radio-frequency reactive magnetron sputtering exhibit the mixture of ferromagnetic and paramagnetic phases at room temperature. The estimated magnetic moment per Er ion decreases with the increase of Er concentration. The temperature dependence of the magnetization indicates that there is no intermetallic ErZn buried in the films. The ferromagnetism is attributed to the Er ions substitution for Zn2+ in ZnO lattices, and it can be interpreted by the bound-magnetic-polaron model
Deadzone compensation control based on detection of micro flow rate in pilot stage of proportional directional valve
The pilot operated proportional directional valves (POPDVs) with a flow rate ranging from 100 to 1000 L/min are widely used in electro-hydraulic systems (EHSs). The deadzone of the pilot stage valve and its control compensation could significantly affect the position control performance for the main stage valve that could directly affect dynamics of EHSs In this paper, it is concluded that micro flow rates exist at the intermediate position of the valve based on the analysis of the continuity equation of the flow in the control chamber of the pilot stage. The micro flow rate is helpful to eliminate the discontinuity and unsmooth domain in the previous inverse deadzone compensation function. An improved deadzone detection method is proposed to calibrate the pilot valve flow characteristics which include the micro flow rate. This new method avoids the threshold selection of the main valve spool displacement which affects the detected deadzone values. Its detection processes are realized based on the pilot flow rate characterized by the speed of the main valve spool and the pilot valve displacement characterized by the solenoid current. The deadzone compensation control strategy based on the improved deadzone detection method is also designed. The experimental results using the steady-state position tracking and sinusoidal position tracking methods are verified. It is concluded that the tracking accuracy of the main valve spool position is effectively improved with this control strategy
Three-dimensional hollow urchin alpha-MnO2 for enhanced catalytic activity towards toluene decomposition in post-plasma catalysis
Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite
As China's first X-ray astronomical satellite, the Hard X-ray Modulation
Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15,
2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy
satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was
designed to perform pointing, scanning and gamma-ray burst (GRB) observations
and, based on the Direct Demodulation Method (DDM), the image of the scanned
sky region can be reconstructed. Here we give an overview of the mission and
its progresses, including payload, core sciences, ground calibration/facility,
ground segment, data archive, software, in-orbit performance, calibration,
background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech.
Astron. arXiv admin note: text overlap with arXiv:1910.0443
Integrating genetic data to examine the link between religious attendance and demographic behaviors in the United States
The connections between religious attendance and various human behaviors have long fascinated social scientists. Recent genomics and statistical genetics advances in the US, where over 60% of the population maintains religious affiliation, have made it possible to explore the genetic underpinnings of religious attendance and its links to demographic behaviors. This dissertation consists of three chapters that delve into the complexities of religious attendance and human behaviors, highlighting the value of integrating genetic data.
In the first chapter, we examine the shared genetic architecture between religious attendance and diverse demographic traits using genome-wide association studies (GWAS) summary statistics and innovative statistical tools such as Genomic SEM and GWAS-by-subtraction. We create polygenic indices (PGI) for religious attendance in three American longitudinal surveys, uncovering a small yet significant PGI impact on religious attendance. Our findings indicate a negative genetic association between religious attendance and high-risk health behaviors, as well as a positive correlation with improved physical and mental health. Further, our Genomic SEM analysis reveals that religious attendance has a positive genetic effect on the number of children, mediated by education and less risky sexual behavior. This chapter highlights the unique nature of religious attendance in comparison to other forms of social interaction and suggests a potential molecular link between religious attendance and health through cell immunity.
Chapter 2 investigates religious assortative mating and differential fertility among older US adults. Despite declining religious attendance and increasing interfaith marriages, we observe a consistent positive phenotypic correlation among spousal pairs but limited evidence of significant religious assortative mating at the genotypic level. We find that the association between religious attendance and fertility is mediated by education, but no direct genetic effect of religious attendance on fertility is evident.
In Chapter 3, we explore gene-environment interactions with respect to adverse life events, religious attendance, and depressive symptoms. Our research reveals that individuals with varying genetic predispositions to religious attendance respond differently to external stressors. High religiosity PGI and more frequent religious attendance serve as protective factors against depression. Collectively, these chapters offer novel insights into the intricate genetic and phenotypic relationships between religious attendance and demographic behaviors, emphasizing the importance of disentangling the genetic and environmental factors shaping these associations
Thermal Performance of Micro Hotplates with Novel Shapes Based on Single-Layer SiO2 Suspended Film
In this paper, two kinds of suspended micro hotplate with novel shapes of multibeam structure and reticular structure are designed. These designs have a reliable mechanical strength, so they can be designed and fabricated on single-layer SiO2 suspended film through a simplified process. Single-layer suspended film helps to reduce power consumption. Based on the new film shapes, different resistance heaters with various widths and thicknesses are designed. Then, the temperature uniformity and power consumption of different micro hotplates are compared to study the effect of these variables and obtain the one with the optimal thermal performance. We report the simulations of temperature uniformity and give the corresponding infrared images in measurement. The experimental temperature differences are larger than those of the simulation. Experimental results show that the lowest power consumption and the minimum temperature difference are 43 mW and 50 °C, respectively, when the highest temperature on the suspended platform (240 × 240 μm2) is 450 °C. Compared to the traditional four-beam micro hotplate, temperature non-uniformity is reduced by about 30–50%