Methods used in teaching wrestling to the blind

Thesis (Ed.M.)--Boston Universit

Interview on \u3cem\u3eThe Black Box Society\u3c/em\u3e

Hidden algorithms drive decisions at major Silicon Valley and Wall Street firms. Thanks to automation, those firms can approve credit, rank websites, and make myriad other decisions instantaneously. But what are the costs of their methods? And what exactly are they doing with their digital profiles of us? Leaks, whistleblowers, and legal disputes have shed new light on corporate surveillance and the automated judgments it enables. Self-serving and reckless behavior is surprisingly common, and easy to hide in code protected by legal and real secrecy. Even after billions of dollars of fines have been levied, underfunded regulators may have only scratched the surface of troublingly monopolistic and exploitative practices. Drawing on the work of social scientists, attorneys, and technologists, The Black Box Society offers a bold new account of the political economy of big data. Data-driven corporations play an ever larger role in determining opportunity and risk. But they depend on automated judgments that may be wrong, biased, or destructive. Their black boxes endanger all of us. Faulty data, invalid assumptions, and defective models can’t be corrected when they are hidden. Frank Pasquale exposes how powerful interests abuse secrecy for profit and explains ways to rein them in. Demanding transparency is only the first step. An intelligible society would assure that key decisions of its most important firms are fair, nondiscriminatory, and open to criticism. Silicon Valley and Wall Street need to accept as much accountability as they impose on others. In this interview with Lawrence Joseph, Frank Pasquale describes the aims and methods of the book

Entanglement scaling and spatial correlations of the transverse field Ising model with perturbations

We study numerically the entanglement entropy and spatial correlations of the one dimensional transverse field Ising model with three different perturbations. First, we focus on the out of equilibrium, steady state with an energy current passing through the system. By employing a variety of matrix-product state based methods, we confirm the phase diagram and compute the entanglement entropy. Second, we consider a small perturbation that takes the system away from integrability and calculate the correlations, the central charge and the entanglement entropy. Third, we consider periodically weakened bonds, exploring the phase diagram and entanglement properties first in the situation when the weak and strong bonds alternate (period two-bonds) and then the general situation of a period of n bonds. In the latter case we find a critical weak bond that scales with the transverse field as $J'_c/J$ = $(h/J)^n$, where $J$ is the strength of the strong bond, $J'$ of the weak bond and $h$ the transverse field. We explicitly show that the energy current is not a conserved quantity in this case.Comment: 9 pages, 12 figures, version accepted in PR

Natural aging and reversion behavior of Al-Cu-Li-Ag-Mg alloy Weldalite (tm) 049

This study was initiated to understand the natural aging and reversion behavior of Weldalite (trademark) 049 in tempers without cold work. Of particular interest are: (1) the microstructural basis for the high strength in the T4 condition; (2) an explanation of the reversion phenomenon; and (3) the effect of re-aging at room temperature after a reversion treatment. Mechanical properties were measured and transmission electron microscopy (TEM) analysis performed at various stages of microstructural development during aging, reversion, and subsequent re-aging

Structure and properties during aging of an Al-Cu-Li-Ag-Mg alloy, Weldalite (tm) 049

An Al-Cu-Li-Ag-Mg alloy, Weldalite (trademark) 049, was recently introduced as an ultra-high strength alloy (7000 MPa yield strength in artificially aged tempers) with good weldability. In addition, the alloy exhibits an extraordinary natural aging response (440 MPa yield strength (YS) in the unstretch condition) and a high ductility reversion condition which may be useful as a cold-forming temper. In contrast to other Al-Li alloys, these properties can essentially be obtained with or without a stretch or other coldworking operation prior to aging. Preliminary studies have revealed that the T4 temper (no stretch, natural age) is strengthened by a combination of GP zones and delta prime (Al3Li). The T6 temper (no stretch, aged at 180 C to peak strength) was reported to be strengthened primarily by T(sub 1) phase (Al2CuLi) with a minor presence of a theta prime like (Al2Cu) phase. On the other hand, a similar but lower solute containing alloy was reported to contain omega, (stoichiometry unknown), theta prime, and S prime in the peak strength condition. The purpose of this study is to further elucidate the strengthening phases in Weldalite (trademark) 049 in the unstretched tempers, and to follow the development of the microstructure from the T4 temper through reversion (180 C for 5 to 45 minutes) to the T6 temper

Effect of Surface Preparation Methods on Mechanical Properties of 3D Structures Fabricated by Stereolithography and 3D Printing for Electroless Ni Plating

Stereolithography (SL) and 3D Printing (3DP) are useful technologies for three-dimensional prototyping applications, providing highly accurate and detailed part geometries with high quality surface finishes. It is desired to improve the materials performance of the existing photocurable SL and 3DP resins for rapid tooling and other functional applications by applying a nickel (Ni) coating. In this work, surface preparation methods for electroless plating of commercial photopolymer resins such as NanoFormTM15120 (NanoForm) and Objet FullCure®840 (Veroblue) were explored in order to enhance the structural integrity of RP components. This study examined different surface preparation methods (chemical etching) and their effect on the surface morphology and mechanical strength of the polymers. It was observed that surface preparation of the resins significantly affected the mechanical properties and Ni plating of the substrate polymers. This is a critical step, since the Ni film takes on the surface structure of the substrate.Mechanical Engineerin

The Gender Gap Cracks Under Pressure: A Detailed Look at Male and Female Performance Differences During Competitions

Using data from multiple-period math competitions, we show that males outperform females of similar ability during the first period. However, the male advantage is not found in any subsequent period of competition, or even after a two-week break from competition. Some evidence suggests that males may actually perform worse than females in later periods. The analysis considers various experimental treatments and finds that the existence of gender differences depends crucially on the design of the competition and the task at hand. Even when the male advantage does exist, it does not persist beyond the initial period of competition.competitiveness, gender differences, effort and productivity, field experiment