Search

Structures are designed with the intention of safely withstanding ordinary and extreme loads over the entire intended economic lifetime. Designation of appropriate design levels is especially difficult for natural processes, for which many decades of reliable data are desirable, but is often basically unattainable. One such area of interest is the prediction of extreme wind speeds. Recently, multiyear, mechanically recorded data from five sites in the Pacific Northwest were obtained. The data consist of hourly 1-s maximum gust speeds, wind direction, temperature, and barometric pressure. Using these variables, the data are examined by season to determine statistical characteristics, including their dependencies. In particular, histograms of the wind gusts are examined in detail at each location to determine whether they can be modeled by a single probability distribution. Statistical time series analysis is traditionally dependent on the assumption that all observations arise from a single distribution, but recent theoretical advances have been made with mixed distributions in extreme value theory. The suitability of the observed wind data for analysis using mixed distributions is examined, and the peaks-over-threshold technique is applied. The results are compared to those obtained by assuming the data arise from a single distribution. Rather striking results indicate the importance of the mixed distribution approach, including seasonal and direction variations. We also note that the theory of mixed distributions in extreme value theory can be applied to any data for which extremal computations are desired. DOI: 10.1061/(ASCE)0733-9445(2003)129:9(1268) CE Database subject headings: Design wind speed; Statistical analysis; Stochastic models; Structural safety; Time series analysis; Wind loads.

Objectives: A remote quality assurance and improvement protocol for point‐of‐care obstetric ultrasound in low‐resource areas was validated against the standard of care for obstetric ultrasound in the United States. Methods: Compressed movie clip ultrasound images (obstetric sweep protocol) obtained by minimally trained personnel were read and interpreted by physicians with training in obstetric ultrasound. Observed findings were compared among readers and between each reader and the gold standard ultrasound scan report. Descriptive statistics were used for the analysis. Results: The agreements among readers and between readers and the gold standard, for the anterior and posterior variables of the placental location were excellent, with Cohen κ values of 0.81 to 0.88 and 0.77 to 0.9, respectively. Cohen κ values were slight or slight/fair for other placental locations (left, right, fundal, and low), and the sensitivity and specificity ranged widely. The agreement among readers and between readers and the gold standard for fetal number comparisons was also excellent, with Cohen κ values ranging from 0.82 to 1, sensitivity from 0.83 to 1, and specificity from 0.99 to 1. The agreement among readers for fetal presentation comparisons, according to the Cohen κ, ranged from 0.79 to 0.85 and between readers and the gold standard had values of 0.43 to 0.49. For biometric parameters and estimated gestational age calculations based on these parameters, inter‐reader reliability ranged from 0.79 to 0.85 for all parameters except femur length. Greater than 94% of obstetric sweep protocol ultrasound ages were within 7 days of the corresponding gold standard age. Conclusions: Movie clip ultrasound images provided adequate information for remote readers to reliably determine the placental location, fetal number, fetal presentation, and pregnancy dating. [ABSTRACT FROM AUTHOR]

Rate-hardness is introduced as a quality metric for hard virtual surfaces, and linked to human perception of hardness via a psychophysical study. A 3 degree-of-freedom haptic interface is used to present pairs of virtual walls to users for side-by-side comparison. 49 subjects are tested in a series of three blocks of trials, where different virtual walls are presented in randomly ordered pairs. Results strongly support the use of rate-hardness, as opposed to mechanical stiffness, as the more relevant metric for haptic interface performance in rendering hard virtual surfaces. It is also shown that common techniques of enhancing stability of the rendered surfaces tend to actually enhance performance as measured by rate-hardness. Index Terms--Control design, haptic interface, haptic perception, hardness, psychophysics, stability, stiffness, virtual surface.

The Association of Professors of Gynecology and Obstetrics Committee on Global Health developed an inclusive definition of global women's health and competency-based objectives that reflected work internationally, as well as with U.S. vulnerable and underserved populations, such as refugee and immigrant populations or those who would otherwise have compromised access to health care. The knowledge, skill, and attitude-based competencies required to fulfill each learning objective were mapped to the Accreditation Council for Graduate Medical Education Outcomes Project's educational domains and the Consortium of Universities for Global Health competency domains. The proposed global women's health definition and competency-based learning objective framework is a first step in ensuring quality standards for educating trainees to address global women's health needs. By proposing these objectives, we hope to guide future program development and spark a broader conversation that will improve health for vulnerable women and shape educational, ethical, and equitable global health experiences for medical trainees. [ABSTRACT FROM AUTHOR]