This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or…
This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or randomly located observations. We next conduct observing system simulation experiments for a chaotic model of meteorological interest, where we demonstrate that the local ensemble transform Kalman filter (LETKF) with targeted observations based on largest ensemble variance is skillful in providing more accurate state estimates than the LETKF with randomly located observations. Additionally, we find that a hybrid ensemble Kalman filter parameter estimation method accurately updates model parameters within the targeted observation context to further improve state estimation.
As obesity rates continue to rise in adolescents and young children, the concern for poor future health of the younger population grows. Physical activity and improving nutrition are two ways to combat obesity rates, and the Sustainability via Active Gardening Education (SAGE) project addresses this in underserved and low-income communities…
As obesity rates continue to rise in adolescents and young children, the concern for poor future health of the younger population grows. Physical activity and improving nutrition are two ways to combat obesity rates, and the Sustainability via Active Gardening Education (SAGE) project addresses this in underserved and low-income communities in Maricopa County. This project employs a curriculum designed to promote physical activity and healthy eating for Early Care and Education (ECE) sites, most of which are daycares. Further, utilizing indicators of future health can also allow for us to understand and lower obesity rates. One indicator of future health is grip strength: greater grip strength is associated with healthier outcomes such as lower triglycerides, blood pressure, and body mass index. Grip strength has been observed in the older population; however, there are few studies looking at grip strength in younger children, namely preschoolers. As grip strength is a predictor of health, it follows that it should be observed in preschoolers, and improved, if possible, by factors such as physical activity, which would ultimately improve obesity rates. This study aimed to see if there was any relationship between physical activity and grip strength in preschoolers aged 3-5 years old. To do so, grip strength, hand length, height, weight, and information regarding physical activity of preschoolers enrolled in the SAGE project were collected.
Physical activity and grip strength were not found to be significantly associated in this study; however, hand length and hand strength were associated. Among secondary outcomes, it was observed that males of ages 3 to 5-years-old may have greater hand grip strength than females of the same age group. Although this was not statistically significant, there was a trend toward statistical significance. Small sample size hampered observation of expected relationships between hand grip strength and dominant hand of the participants, and hand grip strength was not significantly related with BMI. Future directions would consist of collecting longitudinal data, as well as calling back previous years’ participants for additional data, so that there is a larger sample size for data analysis.
