Galaxy-Galaxy Flexion: Weak Lensing to Second Order

In this paper, we develop a new gravitational lensing inversion technique. While traditional approaches assume that the lensing field varies little across a galaxy image, we note that this variation in the field can give rise to a ``Flexion'' or bending of a galaxy image, which may then be used to detect a lensing signal with increased signal to noise. Since the significance of the Flexion signal increases on small scales, this is ideally suited to galaxy-galaxy lensing. We develop an inversion technique based on the ``Shapelets'' formalism of Refregier (2003). We then demonstrate the proof of this concept by measuring a Flexion signal in the Deep Lens Survey. Assuming an intrinsically isothermal distribution, we find from the Flexion signal alone a velocity width of v_c=221\pm 12 km/s for lens galaxies of r < 21.5, subject to uncertainties in the intrinsic Flexion distribution.Comment: 11 pages, Latex, 4 figures. Accepted by ApJ, changes include revision of errors from previous draf

Text mining for classifying workplace severe injury events

Occupational health and safety are significant issues for many organizations. Workplace accidents have significant consequences for employees, and they also cause significant disruptions to business processes. In this paper, we analyze accident narrative data collected by the Occupational Safety and Health Administration (OSHA) to classify events leading to injuries and body parts injured. These datasets are collected in textual form, which can create difficulties for nuanced statistical analyses. By creating high-performing text classifiers, we can automatically code these records and provide decision-makers with useful information. We use BERT word embeddings and several variants thereof to perform these classifications, finding accuracy of approximately 89 percent and 79 percent for event types and body parts respectively. These contributions will improve organizations’ capacities to understand and act upon textual accident narratives

The Galaxy Octopole Moment as a Probe of Weak Lensing Shear Fields

In this paper, we introduce the octopole moment of the light distribution in galaxies as a probe of the weak lensing shear field. While traditional ellipticity estimates of the local shear derived from the quadrupole moment are limited by the width of the intrinsic ellipticity distribution of background galaxies, the dispersion in the intrinsic octopole distribution is expected to be much smaller, implying that the signal from this higher order moment is ultimately limited by measurement noise, and not by intrinsic scatter. We present the computation of the octopole moment and show that current observations are at the regime where the octopole estimates will soon be able to contribute to the overall accuracy of the estimates of local shear fields. Therefore, the prospects for this estimator from future datasets like the Advanced Camera for Survey and the Next Generation Space Telescope are very promising.Comment: 9 pages, 2 PostScript figures; Submitted to Astrophysical Journa

The art of persuasion: An integrated text mining model for crowdfunding analysis

Crowdfunding is a substantial new funding source and growing in popularity, providing a vital service to individuals especially in developing countries, who could not otherwise get the financial resources they need. Understanding factors that determine the funders’ decisions is important in writing persuasive crowdfunding pitches for successful projects. In this paper, we present an integrated text-mining model that combines the bag-of-words model and related variables for predicting the success of crowdfunding projects in Kiva. Furthermore, association rule mining is used to identify factors that influence the funders’ decisions for writing persuasive crowdfunding pitches for successful projects