Reactive Planar Manipulation with Convex Hybrid MPC

This paper presents a reactive controller for planar manipulation tasks that leverages machine learning to achieve real-time performance. The approach is based on a Model Predictive Control (MPC) formulation, where the goal is to find an optimal sequence of robot motions to achieve a desired object motion. Due to the multiple contact modes associated with frictional interactions, the resulting optimization program suffers from combinatorial complexity when tasked with determining the optimal sequence of modes. To overcome this difficulty, we formulate the search for the optimal mode sequences offline, separately from the search for optimal control inputs online. Using tools from machine learning, this leads to a convex hybrid MPC program that can be solved in real-time. We validate our algorithm on a planar manipulation experimental setup where results show that the convex hybrid MPC formulation with learned modes achieves good closed-loop performance on a trajectory tracking problem

Psychometric Evaluation of an Instrument to Measure Hispanic Mothers’ Normative Beliefs, Intentions, Past Experience and Past Behavior Related to the Discussion of Sex-Related Topics with their Adolescent Daughters

Aim: The aim of this project was to describe the psychometric properties of a recently developed instrument that measures Hispanic mother normative beliefs, intentions, past experience, and past behavior regarding the Discussion of Sex-Related Topics (DSRTs) with their adolescent daughters. Background: The DSRTs between Hispanic mothers and their adolescent daughters is important because this interaction has been found to be a protective factor against the daughter’s risk for STDs and unintended pregnancy. Hispanic mother talk less with their daughters about sex-related topics (SRTs) than other ethnic groups. The Rodriguez Normative Belief Instrument (RNBI) has been established to measure normative beliefs, normative beliefs, past behavior, and past experience regarding Hispanic mothers’ DSRTs with their adolescent daughters. Method: The 44-item RNBI was developed based on the Theory of Planned Behavior and the Parent-Based Expansion Theory of Planned Behavior. A convenience sample of 119 Hispanic mothers of adolescent females grades 6 through 8 from two Midwestern Catholic Middle Schools was enrolled completed the instrument. Paper and pen instruments were administered in the language of the participant’s choice, English or Spanish. Results: The entire RNBI and each of the four subscales demonstrated acceptable internal consistency (Cronbach’s alpha = .70). The overall reliability of the RNBI was .82 with the normative beliefs subscale of .85, intentions .88, past behavior .89, and past experience .88. Confirmatory factor analysis validated the four subscales. Conclusion: Psychometric analyses indicated that the RNBI demonstrates acceptable validity and reliability for this sample

Reclaiming this generation for Christ : why do Latino Pentecostal youth abandon their faith after high school?

https://place.asburyseminary.edu/ecommonsatsdissertations/2479/thumbnail.jp

Commutative GG-invariant Toeplitz C∗^\ast algebras on the Fock space and their Gelfand theory through Quantum Harmonic Analysis

We discuss the notion of spectral synthesis for the setting of Quantum Harmonic Analysis. Using these concepts, we study subalgebras of the full Toeplitz algebra with certain invariant symbols and their commutators. In particular, we find a new class of commutative Toeplitz C$^\ast$ algebras on the Fock space. In the end, we investigate the Gelfand theory of those commutative C$^\ast$ algebras.Comment: 26 pages; Comments are welcom

Global Disk Oscillation Modes in Cataclysmic Variables and Other Newtonian Accretors

Diskoseismology, the theoretical study of small adiabatic hydrodynamical global perturbations of geometrically thin, optically thick accretion disks around black holes (and other compact objects), is a potentially powerful probe of the gravitational field. For instance, the frequencies of the normal mode oscillations can be used to determine the elusive angular momentum parameter of the black hole. The general formalism developed by diskoseismologists for relativistic systems can be readily applied to the Newtonian case of cataclysmic variables (CVs). Some of these systems (e.g., the dwarf nova SS Cygni) show rapid oscillations in the UV with periods of tens of seconds and high coherence. In this paper, we assess the possibility that these dwarf nova oscillations (DNOs) are diskoseismic modes. Besides its importance in investigating the physical origin of DNOs, the present work could help us to answer the following question. To what extent are the similarities in the oscillation phenomenology of CVs and X-ray binaries (XRBs) indicative of a common physical mechanism?Comment: 1 figur

On the Perturbations of Viscous Rotating Newtonian Fluids

The perturbations of weakly-viscous, barotropic, non-self-gravitating, Newtonian rotating fluids are analyzed via a single partial differential equation. The results are then used to find an expression for the viscosity-induced normal-mode complex eigenfrequency shift, with respect to the case of adiabatic perturbations. However, the effects of viscosity are assumed to have been incorporated in the unperturbed (equilibrium) model. This paper is an extension of the normal-mode formalism developed by Ipser & Lindblom for adiabatic pulsations of purely-rotating perfect fluids. The formulas derived are readily applicable to the perturbations of thin and thick accretion disks. We provide explicit expressions for thin disks, employing results from previous relativistic analyses of adiabatic normal modes of oscillation. In this case, we find that viscosity causes the fundamental p- and g- modes to grow while the fundamental c-mode could have either sign of the damping rate.Comment: Accepted for publication by The Astrophysical Journal. 11 pages, no figure