734 research outputs found
A Random Walk down Main Street
US suburbs have often been characterized by their
relatively low walk accessibility compared to more urban
environments, and US urban environments have been
characterized by low walk accessibility compared to
cities in other countries. Lower overall density in the
suburbs implies that activities, if spread out, would have
a greater distance between them. But why should
activities be spread out instead of developed
contiguously? This brief research note builds a positive
model for the emergence of contiguous development
along âMain Streetâ to illustrate the trade-offs that
result in the built environment we observe. It then
suggests some policy interventions to place a âthumb
on the scaleâ to choose which parcels will develop in
which sequence to achieve socially preferred outcomes
The Universal Declaration of Human Rights and education for democracy
We are very happy to present this second issue of the Inter-American Journal of Education for Democracy. Producing a peer-reviewed journal has proved a more complicated and demanding task than we originally anticipated, especially considering that most of the work is done on a volunteer basis, that the editorial committee is located in different parts of the continent, and that the process of evaluating the many papers submitted in three different languages creates additional logistical challenges. Nonetheless, and despite the natural growing pains, the Journal is overcoming these and other challenges, and we are already busy preparing the third issue
Orthogonal polynomials, reproducing kernels, and zeros of optimal approximants
We study connections between orthogonal polynomials, reproducing kernel functions, and polynomials P minimizing Dirichletâtype norms â„pfâ1â„α for a given function f . For α â [0,1] (which includes the Hardy and Dirichlet spaces of the disk) and general f , we show that such extremal polynomials are nonâvanishing in the closed unit disk. For negative α , the weighted Bergman space case, the extremal polynomials are nonâvanishing on a disk of strictly smaller radius, and zeros can move inside the unit disk. We also explain how dist Dα (1, f · Pn) , where Pn is the space of polynomials of degree at most n , can be expressed in terms of quantities associated with orthogonal polynomials and kernels, and we discuss methods for computing the quantities in question.This work was supported by NSF under the grant DMS1500675. DS was supported by ERC Grant 2011-ADG-20110209 from EU programme FP2007-2013 and MEC Projects MTM2014-51824-P and MTM2011-24606
Design and Testing of Autonomous Distributed Space Systems
Distributed Space Systems (DSS) are an emerging class of mission designs that enable new scientific and commercial opportunities. In order to enable those new opportunities, these systems will need to have significantly expanded autonomous capabilities compared to their single-spacecraft predecessors. In this paper, we present Distributed Spacecraft Autonomy (DSA) project, a payload on NASAâs Starling spacecraft experiment. We first describe a step-by-step process for characterizing what features are needed in an autonomous DSS, and show how this process applied to DSA. We then describe the Starling mission, a four-spacecraft swarm hosting multiple DSS payloads. We then describe DSA, which will mature in-space networking and autonomous planning technologies to measure topside ionosophere features using data from the Starling spacecraftâs GPS receivers. We describe how DSA will coordinate observations of GPS satellites using Starlingâs underlying communications infrastructure combined with novel DSS technology. The flight validation of DSS technology will provide mature technology to enable future DSS missions
A mind you can count on: validating breath counting as a behavioral measure of mindfulness.
Mindfulness practice of present moment awareness promises many benefits, but has eluded rigorous behavioral measurement. To date, research has relied on self-reported mindfulness or heterogeneous mindfulness trainings to infer skillful mindfulness practice and its effects. In four independent studies with over 400 total participants, we present the first construct validation of a behavioral measure of mindfulness, breath counting. We found it was reliable, correlated with self-reported mindfulness, differentiated long-term meditators from age-matched controls, and was distinct from sustained attention and working memory measures. In addition, we employed breath counting to test the nomological network of mindfulness. As theorized, we found skill in breath counting associated with more meta-awareness, less mind wandering, better mood, and greater non-attachment (i.e., less attentional capture by distractors formerly paired with reward). We also found in a randomized online training study that 4 weeks of breath counting training improved mindfulness and decreased mind wandering relative to working memory training and no training controls. Together, these findings provide the first evidence for breath counting as a behavioral measure of mindfulness
Some , And Possibly All, Scalar Inferences Are Not Delayed: Evidence For Immediate Pragmatic Enrichment
Scalar inferences are commonly generated when a speaker uses a weaker expression rather than a stronger alternative, e.g., John ate some of the apples implies that he did not eat them all. This article describes a visual-world study investigating how and when perceivers compute these inferences. Participants followed spoken instructions containing the scalar quantifier some directing them to interact with one of several referential targets (e.g., Click on the girl who has some of the balloons). Participants fixated on the target compatible with the implicated meaning of some and avoided a competitor compatible with the literal meaning prior to a disambiguating noun. Further, convergence on the target was as fast for some as for the non-scalar quantifiers none and all. These findings indicate that the scalar inference is computed immediately and is not delayed relative to the literal interpretation of some. It is argued that previous demonstrations that scalar inferences increase processing time are not necessarily due to delays in generating the inference itself, but rather arise because integrating the interpretation of the inference with relevant information in the context may require additional time. With sufficient contextual support, processing delays disappear
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