Surrogate modeling a computational fluid dynamics-based wind turbine wake simulation using machine learning

The Wind Farm Layout Optimization problem involves finding the optimal positions for wind turbines on a wind farm site. Current Metahueristic based methods make use of a combination of turbine specifications and parameters, mathematical models and empirically produced power production equations to estimate the energy output of a real wind farm [15]. The overarching variable in any optimisation function is wind speed - this is what used to determine the power generated. Therefore, accurate predictions of wind speeds at specific points across the volume of the site are needed. In this paper, Computational Fluid Dynamics (CFD) was used to simulate a full scale rotating wind turbine blade with fluid (air) at various wind speeds flowing past the turbine. The wake effect can be observed and leads to decrease in wind speeds, as expected. Wind speed at specific x,y and z (3D) coordinates were sampled and used as input to common Machine Learning regression algorithms to create different surrogate models. This was needed as each individual CFD experiment takes approximately 8 hours to complete, so it is not feasible to continuously repeat these simulations inside a metaheuristic optimiser

Jupiter's Metastable Companions

Jovian co-orbitals share Jupiter's orbit in 1:1 mean motion resonance. This includes $>$10,000 so-called Trojan asteroids surrounding the leading (L4) and trailing (L5) Lagrange points, viewed as stable groups dating back to planet formation. Via a massive numerical study we identify for the first time some Trojans which are certainly only `metastable'; instead of being primordial, they are recent captures from heliocentric orbits into moderately long-lived (10 kyr - 100 Myr) metastable states that will escape back to the scattering regime. We have also identified (1) the first two jovian horseshoe co-orbitals that exist for many resonant libration periods, and (2) eight jovian quasi-satellites with metastable lifetimes of 4-130 kyr. Our perspective on the Trojan population is thus now more complex as Jupiter joins the other giant planets in having known metastable co-orbitals which are in steady-state equilibrium with the planet-crossing Centaur and asteroid populations, in agreement with theoretical estimates

A study of effective evaluation models and practices for technology supported physical learning spaces (JELS)

The aim of the JELS project was to identify and review the tools, methods and frameworks used to evaluate technology supported or enhanced physical learning spaces. A key objective was to develop the sector knowledgebase on innovation and emerging practice in the evaluation of learning spaces, identifying innovative methods and approaches beyond traditional post-occupancy evaluations and surveys that have dominated this area to date. The intention was that the frameworks and guidelines discovered or developed from this study could inform all stages of the process of implementing a technology supported physical learning space. The study was primarily targeted at the UK HE sector and the FE sector where appropriate, and ran from September 2008 to March 2009

Early Child Development in Social Context: A Chartbook

Reviews more than 30 key indicators of health and development for children up to age 6, as well as social factors in families and communities that affect these outcomes. Offers practical suggestions for health practitioners and parents

Is African-American Girls’ Perception of their Mother-Daughter Relationship Associated to Psychosocial and Physical Activity Variables?

Maternal influence has been reported to play a significant role in the health behaviors of children. In Caucasian girls, it has been reported that mother-daughter relationship can influence psychosocial variables such as physical activity (PA) self-efficacy. Currently, there is very little data on the impact of African-American girls’ perception of their relationship with their mother and psychosocial variables. PURPOSE: To examine the association between mother-daughter relationship, PA self-efficacy (PA-SE) and PA levels in African-American girls. METHODS: Baseline data from mothers (n=28; age=37.0±6.7 years; BMI=33.5±10.6 kg/m2) and daughters (n=32; age=9.0±1.2 years; BMI=20.4±5.7 kg/m2, 90th percentile) participating in an afterschool mother-daughter PA study was used in this analysis. PA was measured for 7 continuous days using accelerometers. Parental Responsiveness (PR) and Adolescent Openness to Parental Socialization scales were used to assess mother-daughter relationship. Daughters’ self-esteem and depressive symptoms were assessed with the Rosenberg Self-Esteem (RSE) scale and the Child Depression Inventory (CDI), respectively. Participants’ PA-SE was assessed with validated questionnaires. Spearman correlations were used to examine associations between mother-daughter relationship, psychosocial variables, and PA levels. Daughters’ scores for the PR scale were divided into tertiles. Between group (high versus low perception of mother-daughter relationship) differences in psychosocial variables and PA were assessed with t-tests. RESULTS: Daughters’ perception of their mother-daughter relationship was positively correlated with RSE (r=0.36, p=0.04). Daughters’ percent time spent in MVPA was negatively correlated with CDI (r=-0.42, p=0.03) and positively correlated with mothers’ PA-SE (r=0.44, p=0.04). With respect to daughters’ PR scale, significant differences in RSE score (HIGH=23.82±4.33; LOW=18.20±4.87, p=0.01) and percent time spent in sedentary activity (HIGH=27.83±32.31; LOW=57.41±20.93, p=0.02) were observed between tertiles. CONCLUSION: African-American girls’ perception of their relationship with their mother seems to be associated with self-esteem, depressive symptoms and sedentary pursuits. Future studies should target interventions that improve mother-daughter relationship