Episodic Learning with Control Lyapunov Functions for Uncertain Robotic Systems

Many modern nonlinear control methods aim to endow systems with guaranteed properties, such as stability or safety, and have been successfully applied to the domain of robotics. However, model uncertainty remains a persistent challenge, weakening theoretical guarantees and causing implementation failures on physical systems. This paper develops a machine learning framework centered around Control Lyapunov Functions (CLFs) to adapt to parametric uncertainty and unmodeled dynamics in general robotic systems. Our proposed method proceeds by iteratively updating estimates of Lyapunov function derivatives and improving controllers, ultimately yielding a stabilizing quadratic program model-based controller. We validate our approach on a planar Segway simulation, demonstrating substantial performance improvements by iteratively refining on a base model-free controller

It\u27s Not Where You Start, It\u27s How You Finish: Predicting Law School and Bar Success

In this study, we examine the extent to which academic and student engagement factors explain law school grades and first-time bar exam performance. Applying fixed effects linear and logit modeling, our analysis leverages law student transcript data and responses to the Law School Survey of Student Engagement (LSSSE) among students from a diverse group of 20 law schools to estimate academic performance and odds of bar passage. Most notably, we find that GPA improvement during law school is associated with greater odds of passing the bar exam, particularly among students who struggle the most during the first semester. Furthermore, while we find that LSAT scores and undergraduate GPA are predictive (p \u3c 0.05) of both law school performance and bar success (as in previous research), these effects are quite modest. Based on these findings, we propose and discuss several recommendations. These should be helpful to higher education scholars and practitioners, particularly law school deans, administrators, faculty, and academic support staff

It’s Not Where You Start, It’s How You Finish: Predicting Law School and Bar Success

In this study, we examine the extent to which academic and student engagement factors explain law school grades and first-time bar exam performance. Applying fixed effects linear and logit modeling, our analysis leverages law student transcript data and responses to the Law School Survey of Student Engagement (LSSSE) among students from a diverse group of 20 law schools to estimate academic performance and odds of bar passage. Most notably, we find that GPA improvement during law school is associated with greater odds of passing the bar exam, particularly among students who struggle the most during the first semester. Furthermore, while we find that LSAT scores and undergraduate GPA are predictive (p < 0.05) of both law school performance and bar success (as in previous research), these effects are quite modest. Based on these findings, we propose and discuss several recommendations. These should be helpful to higher education scholars and practitioners, particularly law school deans, administrators, faculty, and academic support staff

Estimating the Total Economic Impact of Black Bear Peeling in Western Oregon Using GIS and REMI

In parts of the Pacific Northwest, black bears emerge from winter dens with depleted fat reserves and feed on mature conifers by stripping bark and consuming sugar-rich sapwood. Peeling by bears affects commercial conifers through direct loss of the tree or degraded log quality at stand harvest. Bears generally peel trees from 15-30 years old in intensively managed forests until preferred foods such as fruits and berries are available, and a single bear can peel several trees per day. Dying trees have a signature red canopy and are detected in annual aerial forest health surveys; however, trees that scar over peeling are not detected by aerial surveys. Previous studies reported results of damage summaries for northwest Oregon from flights, adjusted for bias; however, they offered no estimates of economic impact. Using landowner survey data, another study estimated an annual timber loss to bears at approximately $11.5 million across part of western Oregon. While informative, these estimates used broad assumptions to derive primary impacts and did not address secondary impacts. We used aerial health surveys, the national land cover database, and the Regional Economic Models Inc. (REMI) PI+ model to estimate the primary and secondary (indirect and induced) impacts of bear peeling in western Oregon. Because the accuracy and precision of aerial estimates (i.e., percentage of dead trees/polygon) was unknown, we calculated 4 scenarios of loss: 1$0.9-$89 million annually, and resulted in an annual loss of between 11 and 1,012 jobs in the state. We will explain our methodology in this study as well as current efforts to improve the accuracy and precision of damage estimates, and ultimately our understanding of the economic impacts of black bear peeling

An Overview and Tutorial of the Repertory Grid Technique in Information Systems Research

Interest in the repertory grid technique has been growing in the IS field. This article seeks to inform the reader on the proper use and application of the technique in IS research. The methodology has unique advantages that make it suitable for many research settings. In this tutorial, we describe the technique, its theoretical underpinnings, and how it may be used by IS researchers. We conclude by detailing many IS research opportunities that exist in respect to the repertory grid technique

A new genus of Protasteridae (Ophiuridea) from the Lower Devonian Bokkeveld Group of South Africa

Gamiroaster tempestatis, a new genus and species of Palaeozoic ophiuroid, is described from four specimens identified in the Lower DevonianVoorstehoek Formation (Ceres Subgroup, Bokkeveld Group) of SouthAfrica. This ophiuroid belongs the family Protaseridae, a Middle–Late Ordovician taxon that continued into the late Palaeozoic. This new ophiuroid forms part of a much wider fauna of the Malvinokaffric Realm, a biogeographical termused to denote the cool- to cold-water, high-latitude endemic, benthic marine, Devonian faunas of southwestern Gondwana, which also includes the invertebrate fossil assemblages of the Argentine Precordillera and the Fox Bay Formation of the Falkland Islands. The specimens were collected from an obrution deposit excavated on Karbonaatjies farm, ~145 km northeast of Cape Town in theWestern Cape. The excavated rock samples contain >700 articulated specimens of Gamiroaster tempestatis that are closely associated with two types of less common mitrate stylophorans. Silicone casts and high-resolution three-dimensional digital models obtained via micro-CT scanning of these mould fossils provided detailed morphological proxies for this taxonomic description.DST-NRF Centre of Excellence, Palaeosciences (CoE-Pal)JNC201

Assessing the Awareness of Lead Hazards in the Greater Burlington Area

Introduction. Lead is a heavy metal found in and around homes built before 1978, comprising more than 80% of the housing stock in Chittenden County, Vermont. Lead exposure during infancy and childhood can have deleterious effects on development. Our study assessed baseline community understanding of potential household lead hazards in Chittenden County, Vermont. Methods.. 123 paper, 10-question surveys were randomly administered to Chittenden County, VT residents to assess recognition of lead toxicology symptoms and awareness of lead safety programs. Scores were treated as continuous variables, demographically grouped, and analyzed using non-parametric statistical analysis (Mann-Whitney & Kruskal-Wallis). Individual questions were treated as dichotomous variables, demographically grouped and analyzed using chi-squared testing. Results.. 48% of survey participants understood the interaction between ADHD and lead or knew the importance of window maintenance. 54.5% were aware of the Burlington Lead Program\u27s assistance program. Participants earning less than $60,000 and those with less than a graduate degree scored statistically lower (p Conclusion.. Lesser-known lead poisoning symptoms and home interventions that decrease lead exposure should be emphasized to the community. High-risk groups requiring targeted education include those who rent, have lower income and education levels. Primary care providers could serve a larger role in educating patients. Additional efforts should be made to publicize services offered by the Burlington Lead Program.https://scholarworks.uvm.edu/comphp_gallery/1241/thumbnail.jp

A community partnership to evaluate the feasibility of addressing food insecurity among adult patients in an urban healthcare system

BACKGROUND: Food insecurity (FI) is a significant public health problem. Possible sequelae of prolonged food insecurity include kidney disease, obesity, and diabetes. Our objective was to assess the feasibility of a partnership between Henry Ford Health System (HFHS) and Gleaners Community Foodbank of Southeastern Michigan to implement and evaluate a food supplementation intervention initiated in a hospital outpatient clinic setting. METHODS: We established a protocol for using the Hunger Vital Signs to screen HFHS internal medicine patients for food insecurity and established the data sharing infrastructure and agreements necessary for an HFHS-Gleaners partnership that would allow home delivery of food to consenting patients. We evaluated the food supplementation program using a quasi-experimental design and constructing a historical comparison group using the electronic medical record. Patients identified as food insecure through screening were enrolled in the program and received food supplementation twice per month for a total of 12 months, mostly by home delivery. The feasibility outcomes included successful clinic-based screening and enrollment and successful food delivery to consenting patients. Our evaluation compared healthcare utilization between the intervention and historical comparison group during a 12-month observation period using a difference-in-differences (DID) analysis. RESULTS: Of 1691 patients screened, 353 patients (20.9%) met the criteria for FI, of which 340/353 (96.3%) consented, and 256/340 (75.3%) were matched and had data sufficient for analysis. Food deliveries were successfully made to 89.9% of participant households. At follow-up, the intervention group showed greater reductions in emergency department visits than the comparison group, -41.5% and -25.3% reduction, respectively. Similar results were observed for hospitalizations, -55.9% and -17.6% reduction for intervention and control groups, respectively. DID regression analysis also showed lower trends in ED visits and hospitalizations for the intervention group compared to the comparison group. CONCLUSIONS: Results suggest that community-health system partnerships to address patient-reported food insecurity are feasible and potentially could reduce healthcare utilization in these patients. A larger, randomized trial may be the next step in fully evaluating this intervention, perhaps with more outcomes (e.g., medication adherence), and additional covariates (e.g., housing insecurity and financial strain)