The relationship between lifetime health trajectories and socioeconomic attainment in middle age

A large literature demonstrates the direct and indirect influence of health on socioeconomic attainment, and reveals the ways in which health and socioeconomic background simultaneously and dynamically affect opportunities for attainment and mobility. Despite an increasing understanding of the effects of health on social processes, research to date remains limited in its conceptualization and measurement of the temporal dimensions of health, especially in the presence of socioeconomic circumstances that covary with health over time. Guided by life course theory, we use data from the British National Child Development Study, an ongoing panel study of a cohort born in 1958, to examine the association between lifetime health trajectories and socioeconomic attainment in middle age. We apply finite mixture modeling to identify distinct trajectories of health that simultaneously account for timing, duration and stability. Moreover, we employ propensity score weighting models to account for the presence of time-varying socioeconomic factors in estimating the impact of health trajectories. We find that, when poor health is limited to the childhood years, the disadvantage in socioeconomic attainment relative to being continuously healthy is either insignificant or largely explained by time-varying socioeconomic confounders. The socioeconomic impact of continuously deteriorating health over the life course is more persistent, however. Our results suggest that accounting for the timing, duration and stability of poor health throughout both childhood and adulthood is important for understanding how health works to produce social stratification. In addition, the findings highlight the importance of distinguishing between confounding and mediating effects of time-varying socioeconomic circumstances.     

Random effects regression mixtures for analyzing infant habituation

Random effects regression mixture models are a way to classify longitudinal data (or trajectories) having possibly varying lengths. The mixture structure of the traditional random effects regression mixture model arises through the distribution of the random regression coefficients, which is assumed to be a mixture of multivariate normals. An extension of this standard model is presented that accounts for various levels of heterogeneity among the trajectories, depending on their assumed error structure. A standard likelihood ratio test is presented for testing this error structure assumption. Full details of an expectation-conditional maximization algorithm for maximum likelihood estimation are also presented. This model is used to analyze data from an infant habituation experiment, where it is desirable to assess whether infants comprise different populations in terms of their habituation time.     

Fuzzy K-means clustering models for triangular fuzzy time trajectories

We focus our attention on the classification of fuzzy time trajectories with triangular membership function, described by a given set of individuals. To this purpose, we adopt a fullyinformational approach, explicitly recognizing the informational nature shared by the ingredients of the classification procedure: the observed data (Empirical Information) and the classification model (Theoretical Information). In particular, by supposing that the informational paradigm has a fuzzy nature, we suggest three fuzzy clustering models allowing the classification of the triangular fuzzy time trajectories, based on the analysis of the cross sectional and/or longitudinal characteristics of their components (centers and spreads). Two applicative examples are illustrated.     

刚体转动渐进跟踪控制的逆系统方法

逆系统方法是以非线性控制为目的,以直接分析为途径,以动态系统的逆概念为核心。该文将逆系统方法应用于刚体动力学中,运用非线性控制的逆系统方法设计Euler动力学方程的控制器,通过对一个陀螺的外力矩进行实施控制,使刚体在动坐标系下的角速度稳定跟踪指令,来实现对刚体转动的渐进跟踪控制。     

空间光通信ATP技术及其进展

对自由空间激光通信光束自动捕获、跟踪、瞄准（ＡＴＰ）系统的结构与系统主要技术指标进行了分析和讨论。通过对其中典型系统的介绍,进一步描述了ＡＴＰ技术的最新进展,论证了空间激光通信的可行性。     

空间光通信ATP系统设计分析

空间光束捕获、跟踪、瞄准（ＡＴＰ）技术在空间光通信中具有重要地位。文中讨论了空间光通信系统中的ＡＴＰ伺服系统的结构,并对系统稳态设计和系统动态综合等关键问题进行了详细的分析和研究。     

自由空间光通信ATP地面模拟系统研制

自由空间激光通信技术研究关键的步骤之一是通过其地面实验演示系统研究各项关键技术和整体优化技术,并验证它们的性能。文中描述了该地面实验演示系统的一个关键分系统—捕获、跟踪、瞄准（ＡＴＰ）系统的设计、预期达到的性能和未来升级的设想。     

实时专家系统及其应用研究

本文从实时性的角度出发,讨论了实时专家系统的含义,实时推理的特点及其方法并阐述了一个机器人焊接视觉跟踪监控和诊断实时专家系统。     

Does Iconicity in Pictographs Matter? The Influence of Iconicity and Numeracy on Information Processing,Decision Making,and Liking in an Eye‐Tracking Study

Researchers recommend the use of pictographs in medical risk communication to improve people's risk comprehension and decision making. However, it is not yet clear whether the iconicity used in pictographs to convey risk information influences individuals’ information processing and comprehension. In an eye‐tracking experiment with participants from the general population (N = 188), we examined whether specific types of pictograph icons influence the processing strategy viewers use to extract numerical information. In addition, we examined the effect of iconicity and numeracy on probability estimation, recall, and icon liking. This experiment used a 2 (iconicity: blocks vs. restroom icons) × 2 (scenario: medical vs. nonmedical) between‐subject design. Numeracy had a significant effect on information processing strategy, but we found no effect of iconicity or scenario. Results indicated that both icon types enabled high and low numerates to use their default way of processing and extracting the gist of the message from the pictorial risk communication format: high numerates counted icons, whereas low numerates used large‐area processing. There was no effect of iconicity in the probability estimation. However, people who saw restroom icons had a higher probability of correctly recalling the exact risk level. Iconicity had no effect on icon liking. Although the effects are small, our findings suggest that person‐like restroom icons in pictographs seem to have some advantages for risk communication. Specifically, in nonpersonalized prevention brochures, person‐like restroom icons may maintain reader motivation for processing the risk information.     

Incorporating eye tracking into cognitive interviewing to pretest survey questions

In this study, we investigated whether incorporating eye tracking into cognitive interviewing is effective when pretesting survey questions. In the control condition, a cognitive interview was conducted using a standardized interview protocol that included pre-defined probing questions for about one-quarter of the questions in a 52-item questionnaire. In the experimental condition, participants’ eye movements were tracked while they completed an online version of the questionnaire. Simultaneously, their reading patterns were monitored for evidence of response problems. Afterward, a cognitive interview was conducted using an interview protocol identical to that in the control condition. We compared both approaches with regard to the number and types of problems they detected. We found support for our hypothesis that cognitive interviewing and eye tracking complement each other effectively. As expected, the hybrid method was more productive in identifying both questionnaire problems and problematic questions than applying cognitive interviewing alone.