The Uncertainty Aware Salted Kalman Filter: State Estimation for Hybrid Systems with Uncertain Guards

In this paper we present a method for updating robotic state belief through contact with uncertain surfaces and apply this update to a Kalman filter for more accurate state estimation. Examining how guard surface uncertainty affects the time spent in each mode, we derive a guard saltation matrix - which maps perturbations prior to hybrid events to perturbations after - accounting for additional variation in the resulting state. Additionally, we propose the use of parameterized reset functions - capturing how unknown parameters change how states are mapped from one mode to the next - the Jacobian of which accounts for the additional uncertainty in the resulting state. The accuracy of these mappings is shown by simulating sampled distributions through uncertain transition events and comparing the resulting covariances. Finally, we integrate these additional terms into the "uncertainty aware Salted Kalman Filter", uaSKF, and show a peak reduction in average estimation error by 24-60% on a variety of test conditions and systems.Comment: To appear in IROS 202

The ferroelectric Mott-Hubbard phase of organic (TMTTF)2X conductors

We present experimental evidences for a ferro-electric transition in the family of quasi one- dimensional conductors (TMTTF)2X. We interpret this new transition in the frame of the combined Mott-Hubbard state taking into account the double action of the spontaneous charge disproportionation on the TMTTF molecular stacks and of the X anionic potentials

Submergence in a Two-Foot Parshall Flume

The primary objective in this study was to ascertain the validity of the method of analyzing submergence developed by Hyatt (1965) in a standard 2-foot Parshall flume. The method of analyzing submergence was first developed for a trapezoidal flume (Hyatt, 1965), was later verified for a rectangular flume (Skogerboe, walker and Robinson, 1965), and has been shown by the authors to be valid for small Parshall flumes (Skogerboe, Hyatt, Johnson, and England, 1965). In view of previous findings, it was felt the method would also be valid for large Parshall flumes, and for this purpose the 2-foot flume was selected. One other objective of the study was to analyze the possibility that another, or possibly better, point of downstream measurement might be found. To accomplish this, two other points, designated c and d, were selected downstream. The downstream depth measurement is usually taken in the throat as a referenced point designated b. The resulting equations and calibration curve are listed in this report

Measuring Water with Parshall Flumes

Preface: As the value of water increases, the extent to which measurement is employed in an irrigation system also increases. Additional flow measurements provide information for improved management of the water supply. Good water management requires accurate measurement. Many devices have been developed for this purpose and are in use. Included among them are weirs, orifices, calibrated gates, Parshall flumes, and current meters. Of these, the Parshall flume is one of the most widely accepted and used. Presented in this publication is a discussion concerning the use of Parshall flumes for measuring water, including the utilization of a new approach for treating submerged flow that was developed at Utah State University. The information presented on free flow has been taken from the origianl publications of Ralph L. Parshall, and the bulletin, Measurement of Irrigation Water, prepared by Eldon M. Stock. Utilizing data developed by Ralph L. Parshall, A. R. Robinson, and the authors

Submerged Parshall Flumes of Small Size

The calibration of small Parshall flumes for measuring flows ranging in magnitude from 0.1 to 1.1 cubic feet per second (cfs) was accomplished by A. R. Robinson (1960) at Colorado State University. The purpose of Robinson’s investigation was to accurately calibrate and standardize the design of small Parshall measuring flumes. The rated flumes were constructed of galvanized sheet metal. Data was collected for Parshall flumes having throat widths of 1-, 2-, and 3- inches. Calibration tables or curves were prepared for both free and submerged flow. The dimensions of the Parshall flumes rated by Robinson are shown in Figure 1. The study reported herein was made to illustrate that the analysis of submergence developed at Utah State University (Hyatt, 1965) for trapezoidal flumes is applicable to small Parshall flumes. The data reported by Robinson (1960) is analyzed by the submergence parameters reported by Hyatt (1965) and the resulting equations and calibration curves are listed in this report

Recruitment activities for a nationwide, population-based, group-randomized trial: the VA MI-Plus study

BACKGROUND: The Veterans Health Administration (VHA) oversees the largest integrated healthcare system in the United States. The feasibility of a large-scale, nationwide, group-randomized implementation trial of VHA outpatient practices has not been reported. We describe the recruitment and enrollment of such a trial testing a clinician-directed, Internet-delivered intervention for improving the care of postmyocardial infarction patients with multiple comorbidities. METHODS: With a recruitment goal of 200 eligible community-based outpatient clinics, parent VHA facilities (medical centers) were recruited because they oversee their affiliated clinics and the research conducted there. Eligible facilities had at least four VHA-owned and -operated primary care clinics, an affiliated Institutional Review Board (IRB), and no ongoing, potentially overlapping, quality-improvement study. Between December 2003 and December 2005, in two consecutive phases, we used initial and then intensified recruitment strategies. RESULTS: Overall, 48 of 66 (73%) eligible facilities were recruited. Of the 219 clinics and 957 clinicians associated with the 48 facilities, 168 (78%) clinics and 401 (42%) clinicians participated. The median time from initial facility contact to clinic enrollment was 222 days, which decreased by over one-third from the first to the second recruitment phase (medians: 323 and 195 days, respectively; p \u3c .001), when more structured recruitment with physician recruiters was implemented and a dedicated IRB manager was added to the coordinating center staff. CONCLUSIONS: Large group-randomized trials benefit from having dedicated physician investigators and IRB personnel involved in recruitment. A large-scale, nationally representative, group-randomized trial of community-based clinics is feasible within the VHA or a similar national healthcare system

Sequential Sampling Models of Choice: Some Recent Advances

Choice models in marketing and economics are generally derived without specifying the underlying cognitive process of decision making. This approach has been successfully used to predict choice behavior. However, it has not much to say about such aspects of decision making as deliberation, attention, conflict, and cognitive limitations and how these influence choices. In contrast, sequential sampling models developed in cognitive psychology explain observed choices based on assumptions about cognitive processes that return the observed choice as the terminal state. We illustrate three advantages of this perspective. First, making explicit assumptions about underlying cognitive processes results in measures of deliberation, attention, conflict, and cognitive limitation. Second, the mathematical representations of underlying cognitive processes imply well documented departures from Luce’s Choice Axiom such as the similarity, compromise, and attraction effects. Third, the process perspective predicts response time and thus allows for inference based on observed choices and response times. Finally, we briefly discuss the relationship between these cognitive models and rules for statistically optimal decisions in sequential designs