4,438 research outputs found
What You Do in High School Matters: The Effects of High School GPA on Educational Attainment and Labor Market Earnings in Adulthood
Using abstracted grades and other data from Add Health, we investigate the effects of cumulative high school GPA on educational attainment and labor market earnings among a sample of young adults (ages 24-34). We estimate several models with an extensive list of control variables and high school fixed effects. Results consistently show that high school GPA is a positive and statistically significant predictor of educational attainment and earnings in adulthood. Moreover, the effects are large and economically important for each gender. Interesting and somewhat unexpected findings emerge for race. Various sensitivity tests support the stability of the core findings.High school grades; Educational attainment; Earnings; Panel data
Computational Topology Techniques for Characterizing Time-Series Data
Topological data analysis (TDA), while abstract, allows a characterization of
time-series data obtained from nonlinear and complex dynamical systems. Though
it is surprising that such an abstract measure of structure - counting pieces
and holes - could be useful for real-world data, TDA lets us compare different
systems, and even do membership testing or change-point detection. However, TDA
is computationally expensive and involves a number of free parameters. This
complexity can be obviated by coarse-graining, using a construct called the
witness complex. The parametric dependence gives rise to the concept of
persistent homology: how shape changes with scale. Its results allow us to
distinguish time-series data from different systems - e.g., the same note
played on different musical instruments.Comment: 12 pages, 6 Figures, 1 Table, The Sixteenth International Symposium
on Intelligent Data Analysis (IDA 2017
Private Child Support: Current and Potential Impacts
This paper examines the effects of a number of methods for enhancing private child support collections: increasing the proportion of those children potentially eligible for child support who get child support awards; using a uniform standard for determining child support obligations; and collecting a greater percentage of current obligations. The paper also estimates the potential of all three methods used in combination to provide income to needy custodial families.
The research demonstrates that the current private child support system falls far short of its potential to transfer income from noncustodial to custodial families. Although the use of a normative standard, improved collections, and extending child support to all those potentially eligible will greatly improve the economic circumstances of impoverished custodial families, private child support cannot be viewed as the sole answer for the economic plight of these families. Increased work opportunities and increased public support are also needed
Quantifying structure in networks
We investigate exponential families of random graph distributions as a
framework for systematic quantification of structure in networks. In this paper
we restrict ourselves to undirected unlabeled graphs. For these graphs, the
counts of subgraphs with no more than k links are a sufficient statistics for
the exponential families of graphs with interactions between at most k links.
In this framework we investigate the dependencies between several observables
commonly used to quantify structure in networks, such as the degree
distribution, cluster and assortativity coefficients.Comment: 17 pages, 3 figure
Urban encounters: juxtapositions of difference and the communicative interface of global cities
This article explores the communicative interface of global cities, especially as it is shaped in the juxtapositions of difference in culturally diverse urban neighbourhoods. These urban zones present powerful examples, where different groups live cheek by jowl, in close proximity and in intimate interaction — desired or unavoidable. In these urban locations, the need to manage difference is synonymous to making them liveable and one's own. In seeking (and sometimes finding) a location in the city and a location in the world, urban dwellers shape their communication practices as forms of everyday, mundane and bottom-up tactics for the management of diversity. The article looks at three particular areas where cultural diversity and urban communication practices come together into meaningful political and cultural relations for a sustainable cosmopolitan life: citizenship, imagination and identity
Electromagnetically induced transparency and four-wave mixing in a cold atomic ensemble with large optical depth
We report on the delay of optical pulses using electromagnetically induced
transparency in an ensemble of cold atoms with an optical depth exceeding 500.
To identify the regimes in which four-wave mixing impacts on EIT behaviour, we
conduct the experiment in both rubidium 85 and rubidium 87. Comparison with
theory shows excellent agreement in both isotopes. In rubidium 87, negligible
four-wave mixing was observed and we obtained one pulse-width of delay with 50%
efficiency. In rubidium 85, four-wave-mixing contributes to the output. In this
regime we achieve a delay-bandwidth product of 3.7 at 50% efficiency, allowing
temporally multimode delay, which we demonstrate by compressing two pulses into
the memory medium.Comment: 8 pages, 6 figure
Optically guided linear Mach Zehnder atom interferometer
We demonstrate a horizontal, linearly guided Mach Zehnder atom interferometer
in an optical waveguide. Intended as a proof-of-principle experiment, the
interferometer utilises a Bose-Einstein condensate in the magnetically
insensitive |F=1,mF=0> state of Rubidium-87 as an acceleration sensitive test
mass. We achieve a modest sensitivity to acceleration of da = 7x10^-4 m/s^2.
Our fringe visibility is as high as 38% in this optically guided atom
interferometer. We observe a time-of-flight in the waveguide of over half a
second, demonstrating the utility of our optical guide for future sensors.Comment: 6 pages, 3 figures. Submitted to Phys. Rev.
A Pilot Study with a Novel Setup for Collaborative Play of the Humanoid Robot KASPAR with children with autism
This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.This article describes a pilot study in which a novel experimental setup, involving an autonomous humanoid robot, KASPAR, participating in a collaborative, dyadic video game, was implemented and tested with children with autism, all of whom had impairments in playing socially and communicating with others. The children alternated between playing the collaborative video game with a neurotypical adult and playing the same game with the humanoid robot, being exposed to each condition twice. The equipment and experimental setup were designed to observe whether the children would engage in more collaborative behaviours while playing the video game and interacting with the adult than performing the same activities with the humanoid robot. The article describes the development of the experimental setup and its first evaluation in a small-scale exploratory pilot study. The purpose of the study was to gain experience with the operational limits of the robot as well as the dyadic video game, to determine what changes should be made to the systems, and to gain experience with analyzing the data from this study in order to conduct a more extensive evaluation in the future. Based on our observations of the childrens’ experiences in playing the cooperative game, we determined that while the children enjoyed both playing the game and interacting with the robot, the game should be made simpler to play as well as more explicitly collaborative in its mechanics. Also, the robot should be more explicit in its speech as well as more structured in its interactions. Results show that the children found the activity to be more entertaining, appeared more engaged in playing, and displayed better collaborative behaviours with their partners (For the purposes of this article, ‘partner’ refers to the human/robotic agent which interacts with the children with autism. We are not using the term’s other meanings that refer to specific relationships or emotional involvement between two individuals.) in the second sessions of playing with human adults than during their first sessions. One way of explaining these findings is that the children’s intermediary play session with the humanoid robot impacted their subsequent play session with the human adult. However, another longer and more thorough study would have to be conducted in order to better re-interpret these findings. Furthermore, although the children with autism were more interested in and entertained by the robotic partner, the children showed more examples of collaborative play and cooperation while playing with the human adult.Peer reviewe
Modulational instability of spinor condensates
We demonstrate, analytically and numerically, that the ferromagnetic phase of
the spinor Bose-Einstein condenstate may experience modulational instability of
the ground state leading to a fragmentation of the spin domains. Together with
other nonlinear effects in the atomic optics of ultra-cold gases (such as
coherent photoassociation and four-wave mixing) this effect provides one more
analogy between coherent matter waves and light waves in nonlinear optics.Comment: 4 pages, 4 figures. Accepted for Phys. Rev. A Rapid Communication
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