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Objectives: Transcerebellar diameter (TCD) has been utilized prenatally as a tool to estimate gestational age (GA) when fetal growth aberrations are suspected. Traditionally, first trimester ultrasound (1TUS) has been the gold standard of dating a pregnancy in spontaneous pregnancies. We sought to determine if neonatal TCD measurement was as accurate as 1TUS in the estimation of postconceptual gestational age (PCGA). Methods: A retrospective cohort from a registry of high‐quality transmastoid views of consecutive patients from July 2019 to November 2020, delivered from 24 to 34 weeks GA, and with a 1TUS were included. The reference PCGA was the sum of the GA at delivery by 1TUS and day of life. The PCGA by TCD was calculated from Chang et al for GA by TCD. Reference and experimental values were compared by correlation, agreement within 7 days, and Bland–Altman analysis. Results: Of the 154 individual patients in the registry of high‐quality transmastoid views during the study period, 62 met inclusion and exclusion criteria. PCGA by 1TUS and TCD were highly correlated (r = 0.86, P <.001; κ = 47% agreement within 7 days of PCGA). The bias of PCGA by TCD was 4.6 days earlier than the PCGA by 1TUS (95% confidence interval of agreement: −29.2, 20). Conclusions: PCGA estimation by neonatal transmastoid TCD was highly correlated with that of 1TUS. It generally underestimates GA by 4.6 days. This relationship warrants further investigation to determine if this method of estimating PCGA in undated gestations is generalizable. [ABSTRACT FROM AUTHOR]

Slug flow processes draw much attention in chemical and pharmaceutical manufacturing thanks to their ability to eliminate downtime costs and batch‐to‐batch variation. Using in‐line video can monitor the current process status and improve the stability of the slug flow. However, there are no effective image processing methods aiming at such videos from chemical experiments due to limited training sample size and the variety of experimental settings. The paper proposes a training‐free method to automatically detect and measure the slugs from in‐line videos. Multiple image features are fused to identify the slug shapes under various lighting conditions, a six‐point model is fitted to achieve better volume estimation, and a consistency score is estimated to quantify the detection uncertainty. The proposed algorithm achieves similar results to manual labeling for various types of slug flow processes, improving the accuracy of slug column estimation by a large margin compared to the existing automatic methods. Finally, using it to monitor the slug flow process's stability and the change of the slug volume in an injection point are demonstrated. The method not only shows that handcrafted image features have the capability for detection and segmentation from chemical experiment images but also paves the road for a training‐based algorithm for the task. [ABSTRACT FROM AUTHOR]

This paper addresses the trajectory tracking control problem of a quadrotor under uncertain model parameters, external disturbances, and unmeasurable linear velocity. The main contribution of this paper is to present a geometric control strategy with a simple structure and easily adjustable parameters, which combines the differentiator and uncertainty and disturbance estimator techniques to achieve global trajectory tracking control. First, a cascade control framework is introduced to solve the strong coupling and under actuated problems of quadrotors. Furthermore, an anti disturbance outer-loop differentiator-based position controller is designed based on the uncertainty and disturbance estimators (UDE) to achieve accurate quadrotor tracking of the desired trajectory. The higher order control inputs of the translational dynamics are estimated using a differentiator to determine the desired angular velocity and its derivative. Then, a robust inner-loop geometric controller is derived in Lie algebraic space using the rotation matrix. After that, the stability analysis of the closed-loop system is executed using the Lyapunov stability theory. Finally, the numerical simulation verifies that the method enables the quadrotor to have strong robustness and excellent tracking capability in the presence of large initial angles, time-varying disturbances, and unmeasured linear velocity. [ABSTRACT FROM AUTHOR]

We study the Pearson correlation coefficient in a logarithmic manner under the presence of multiplicative distortion measurement errors. In this context, the observed variables with logarithmic transformation are distorted in multiplicative fashions by an observed confounding variable. The proposed multiplicative distortion model in this paper is applied to analyze positive variables. We utilize the conditional mean calibration and the conditional absolute mean calibration methods to obtain the calibrated variables. Furthermore, we propose confidence intervals based on asymptotic normality, empirical likelihood, and jackknife empirical likelihood. Simulation studies demonstrate the effectiveness of the proposed estimation procedure, and a real‐world example is analyzed to illustrate its practical application. [ABSTRACT FROM AUTHOR]

In this investigation, three subjects are considered. First, the effect of the human factor is examined. In carrying out analyses of fatigue delamination propagation tests on laminate composites, the delamination length must be measured. The human effect on measurement of the delamination length a by different investigators is discussed. A limited influence of the human factor on the measurement of the delamination length a, as well as on delamination propagation rate da/dN, is observed in this study. Secondly, the paper proceeds to discuss the influence of the R‐ratio on the fatigue delamination growth rate. It is found that a higher rate of crack/delamination propagation is associated with lower R‐ratios which appears to contradict conventional wisdom. This behavior is confirmed in tests. Thirdly, a comparison between the fatigue propagation rates of two material systems is considered. It is concluded that the energy release rate used to assess these materials should not be normalized. Highlights: Impact of human factor on fatigue delamination tests in laminate composites.Limited influence of the human factor on delamination length and propagation rate.The lower the R‐ratio, the higher the delamination propagation rate.The crack driving force for laminates should be taken as GImax. [ABSTRACT FROM AUTHOR]