Automated Quantitative Description of Spiral Galaxy Arm-Segment Structure

We describe a system for the automatic quantification of structure in spiral galaxies. This enables translation of sky survey images into data needed to help address fundamental astrophysical questions such as the origin of spiral structure---a phenomenon that has eluded theoretical description despite 150 years of study (Sellwood 2010). The difficulty of automated measurement is underscored by the fact that, to date, only manual efforts (such as the citizen science project Galaxy Zoo) have been able to extract information about large samples of spiral galaxies. An automated approach will be needed to eliminate measurement subjectivity and handle the otherwise-overwhelming image quantities (up to billions of images) from near-future surveys. Our approach automatically describes spiral galaxy structure as a set of arcs, precisely describing spiral arm segment arrangement while retaining the flexibility needed to accommodate the observed wide variety of spiral galaxy structure. The largest existing quantitative measurements were manually-guided and encompassed fewer than 100 galaxies, while we have already applied our method to more than 29,000 galaxies. Our output matches previous information, both quantitatively over small existing samples, and qualitatively against human classifications from Galaxy Zoo.Comment: 9 pages;4 figures; 2 tables; accepted to CVPR (Computer Vision and Pattern Recognition), June 2012, Providence, Rhode Island, June 16-21, 201

Scalable Automated Detection of Spiral Galaxy Arm Segments

Given an approximately centered image of a spiral galaxy, we describe an entirely automated method that finds, centers, and sizes the galaxy and then automatically extracts structural information about the spiral arms. For each arm segment found, we list the pixels in that segment and perform a least-squares fit of a logarithmic spiral arc to the pixels in the segment. The algorithm takes about 1 minute per galaxy, and can easily be scaled using parallelism. We have run it on all ~644,000 Sloan objects classified as "galaxy" and large enough to observe some structure. Our algorithm is stable in the sense that the statistics across a large sample of galaxies vary smoothly based on algorithmic parameters, although results for individual galaxies can sometimes vary in a non-smooth but easily understood manner. We find a very good correlation between our quantitative description of spiral structure and the qualitative description provided by humans via Galaxy Zoo. In addition, we find that pitch angle often varies significantly segment-to-segment in a single spiral galaxy, making it difficult to define "the" pitch angle for a single galaxy. Finally, we point out how complex arm structure (even of long arms) can lead to ambiguity in defining what an "arm" is, leading us to prefer the term "arm segments".Comment: 4 pages (twocolumn),5 figures, 2 tables. Submitted to ApJ. Letter

Resource allocation in a university environment : a test of the Ruefli, Freeland, and Davis goal programming decomposition algorithms / BEBR No. 735

Bibliography: p. 20-22

Short research report : a comparison of emotional intelligence levels between students in experiential and didactic college programs

Short Research Report: A Comparison of Emotional Intelligence Levels between Students in Experiential and Didactic College Programspeer-reviewe

Is There a Difference Between Democrat and Republican States in the Number of Female Students Who Experienced Cyberbullying?

In the United States, cyberbullying has become a major public health concern. Because there is a difference between the Democrat Party and the Republican Party on their philosophies involving laws and government interventions related to the control of electronic communications, it is important to know if there is a difference between political partisanship and cyberbullying. Data were collected in 2011, 2013, 2015, and 2017 using a three-stage cluster sample design, which produced a nationally representative sample of students in grades 9–12 who attended public and private schools. Initially, this study employed Poisson regression, which is a parametric statistic, in an attempt to answer the research question. However, the model did not adequately fit the data. As a result, another approach was employed using a nonparametric statistic. As an alternative to avoid the distributional assumptions associated with Poisson regression, generalized estimating equations (GEE) was used. The findings revealed that there was no significant difference between political parties and the percentage of female students who were electronically bullied in their respective jurisdictions

Is There a Relationship Between the Number of Female Students Who Were Cyberbullied and the Number of Female Students Who Seriously Considered Attempting Suicide?

In the United States, cyberbullying has become a major public health concern. Indeed, many people who are victims of cyberbullying consider harming themselves. Because criminal justice practitioners are concerned with public safety, this is an area worthy of study. The general purpose of this study is to investigate whether there is a correlation between the percentage of female students who were electronically bullied and the percentage of female students who seriously considered suicide. Data were collected in 2011, 2013, 2015, and 2017 using a three-stage cluster sample design, which produced a nationally representative sample of students in grades 9–12 who attended public and private schools. As an alternative to avoid the distributional assumptions of independent observations, this study used generalized estimating equations (GEE). The findings revealed that there was no significant difference between the percentage of female students who were electronically bullied and the percentage of female students who seriously considered suicide

Effects of atmospheric aerosols on scattering reflected visible light from earth resouce features

The purpose of this investigation was to identify the vertical variations in atmospheric light attenuation under ambient conditions and to provide a method through which aerial photographs of earth features might be corrected to yield quantitative information about the actual features. A theoretical equation has been developed based on the Bouguer-Lambert extinction law and basic photographic theory. This provided a relationship between the actual density of the photographic negative of an object (D0), the density (D) of the same object at a given altitude (X), and the coefficient of extinction of light (b). This equation states that where 1D, 1B, and 10 are determined from the measurable Hurter and Driffield characteristic curve of the photographic material. Measurements were made of the initial density produced by the energy reflected from control targets on the ground and the density produced by the energy received at flight altitudes through the use of photography. Measurements of the loss of energy at different altitudes due to light scattering in the vertical were made by an integrating nephelometer. These independent measurements were compared through the theoretical equation developed. The theoretical equation has been found to hold for the altitudes studied (altitudes up to 9000 feet above the ground) within the experimental accuracy of the experiments performed. The overall research effort has provided the following important information. 1. It has provided a method to determine the accumulative bX between the ground and an altitude, X, based on ground density data and aerial ·density data. As a result the average b can be determined. 2. For remote sensing of the environment, it has provided a method through which aerial photographs of earth features can be corrected for the attenuation of light due to an aerosol layer between the ground and the altitude specified, provided the coefficient of extinction of the layer is known