The nature of multiple solutions for surface wind speed over the oceans from scatterometer measurements

The satellite SEASAT-A will carry a radar scatterometer in order to measure microwave backscatter from the sea surface. From pairs of radar measurements at angles separated by 90 deg in azimuth the surface wind speed and direction may be inferred, though not uniquely. The character of the solutions for wind speed and direction is displayed, as well as the nature of the ambiguities of these solutions. An economical procedure for handling such data is described, plus a criterion for the need for conventional (surface) data in order to resolve the ambiguities of solutions

Feedback laws for fuel minimization for transport aircraft

The Theoretical Mechanics Branch has as one of its long-range goals to work toward solving real-time trajectory optimization problems on board an aircraft. This is a generic problem that has application to all aspects of aviation from general aviation through commercial to military. Overall interest is in the generic problem, but specific problems to achieve concrete results are examined. The problem is to develop control laws that generate approximately optimal trajectories with respect to some criteria such as minimum time, minimum fuel, or some combination of the two. These laws must be simple enough to be implemented on a computer that is flown on board an aircraft, which implies a major simplification from the two point boundary value problem generated by a standard trajectory optimization problem. In addition, the control laws allow for changes in end conditions during the flight, and changes in weather along a planned flight path. Therefore, a feedback control law that generates commands based on the current state rather than a precomputed open-loop control law is desired. This requirement, along with the need for order reduction, argues for the application of singular perturbation techniques

Women’s use of Preventive Primary Care in the Late Postpartum Period

The literature has limited data on how women access health care after the traditional postpartum period (postpartum). Modeled after a paper by Bryant (2016), this project assesses the prevalence of primary care visits in the late postpartum period (LPP)(60- 730 days postpartum). Study objectives included (1) Identify demographics of general delivering population at UVMMC compared to patients with UVM-affiliated primary care provider (UVMPCP). (2) Understand how the general delivering population uses the UVMHN LPP (3) Among women with a UVM-affiliated PCP, identify the prevalence of preventive care visits in the LPP. (4) Identify characteristics associated with LPP visit attendance. Hypothesis: Women with an established PCP prior to pregnancy are more likely to attend preventive PCP LPP visits. This was a retrospective cohort study for all women who delivered at UVMMC between 7/1/2015-6/30/2017. Data was extracted from Epic EMR. During the study period, 4169 women had one singleton pregnancy, 3413 (82%) had a known PCP, and 1279 (31%) had UVMPCP. 2535 (61%) of all delivering singleton women and 1112 (87%) of UVMPCP women had at least one clinical visit within UVMHN in the LPP. 959 (75%) of UVMPCP women had a LPP PCP visit, and 382 patients (30%) had preventative PCP LPP visits. Our hypothesis was rejected (OR 0.930), but attending any LPP PCP visit was associated with having a PCP established prior to pregnancy (OR 1.684). Attending preventive PCP visit was associated with having the same delivering provider as PCP (OR 1.742), a pre-pregnancy PCP visit (OR 1.460), a PCP visit during prenatal time (OR 1.459), ED visit early postpartum period (OR 0.402), a fetal or neonatal demise (OR 0.445), being single (0.601), and with public insurance (OR 0.489). Further work in understanding these associations will be important in developing improved transition of care models and increasing overall engagement in women’s preventive medicine