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

Optical-approximation analysis of sidewall-spacing effects on the force between two squares with parallel sidewalls

Using the ray-optics approximation, we analyze the Casimir force in a two dimensional domain formed by two metallic blocks adjacent to parallel metallic sidewalls, which are separated from the blocks by a finite distance h. For h > 0, the ray-optics approach is not exact because diffraction effects are neglected. Nevertheless, we show that ray optics is able to qualitatively reproduce a surprising effect recently identified in an exact numerical calculation: the force between the blocks varies non-monotonically with h. In this sense, the ray-optics approach captures an essential part of the physics of multi-body interactions in this system, unlike simpler pairwise-interaction approximations such as PFA. Furthermore, by comparison to the exact numerical results, we are able to quantify the impact of diffraction on Casimir forces in this geometry

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

Logic Integer Programming Models for Signaling Networks

We propose a static and a dynamic approach to model biological signaling networks, and show how each can be used to answer relevant biological questions. For this we use the two different mathematical tools of Propositional Logic and Integer Programming. The power of discrete mathematics for handling qualitative as well as quantitative data has so far not been exploited in Molecular Biology, which is mostly driven by experimental research, relying on first-order or statistical models. The arising logic statements and integer programs are analyzed and can be solved with standard software. For a restricted class of problems the logic models reduce to a polynomial-time solvable satisfiability algorithm. Additionally, a more dynamic model enables enumeration of possible time resolutions in poly-logarithmic time. Computational experiments are included

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

Contours of Inclusion: Frameworks and Tools for Evaluating Arts in Education

This collection of essays explores various arts education-specific evaluation tools, as well as considers Universal Design for Learning (UDL) and the inclusion of people with disabilities in the design of evaluation instruments and strategies. Prominent evaluators Donna M. Mertens, Robert Horowitz, Dennie Palmer Wolf, and Gail Burnaford are contributors to this volume. The appendix includes the AEA Standards for Evaluation. (Contains 10 tables, 2 figures, 30 footnotes, and resources for additional reading.) This is a proceedings document from the 2007 VSA arts Research Symposium that preceded the American Evaluation Association's (AEA) annual meeting in Baltimore, MD

Student protests. Three periods of university governance

Exploring the idea of student protests as an autonomous object of research and discussion, this paper leads to the understanding that the transforming role of the university and its governance defines the possibilities for the political role of students. In this perspective, there is a particular constellation of the different forms of higher education governance that provides students with the right and even the responsibility of protesting as politically engaged citizens of the university and of the state. Approaching the transformation of the models of university governance as a set of archaeologically organised states this paper identifies the sequential roles provided to the students and the meaning of their protests and demonstrations. After visiting some antecedents of more contemporaneous student movements and protests, this paper focuses on the UK to explore three manifestations of university governance that can be roughly differentiated as the enduring democratic period that extends from the late 1960s to the late 1980s, the globalisation period that extends from the early 1990s to the mid-2000s and as the post-millennial turn. These periods, embodying three different styles of governance of higher education, not only demonstrate conformity with the political and economic contexts in which they are embedded, they also correspond to particular socio-technological and communicative ecosystems and determine the specifici-ties of the role of the students and their capacity for political actio