Georgia College & State University

About: Georgia College & State University is a education organization based out in Milledgeville, Georgia, United States. It is known for research contribution in the topics: Population & Higher education. The organization has 950 authors who have published 1591 publications receiving 37027 citations.

Initial results from NuSTAR observations of the Norma arm

Abstract: Results are presented for an initial survey of the Norma Arm gathered with the focusing hard X-Ray Telescope NuSTAR. The survey covers 0.2 deg^2 of sky area in the 3-79 keV range with a minimum and maximum raw depth of 15 ks and 135 ks, respectively. Besides a bright black-hole X-ray binary in outburst (4U 1630–47) and a new X-ray transient (NuSTAR J163433–473841), NuSTAR locates three sources from the Chandra survey of this region whose spectra are extended above 10 keV for the first time: CXOU J163329.5–473332, CXOU J163350.9–474638, and CXOU J163355.1–473804. Imaging, timing, and spectral data from a broad X-ray range (0.3-79 keV) are analyzed and interpreted with the aim of classifying these objects. CXOU J163329.5–473332 is either a cataclysmic variable or a faint low-mass X-ray binary. CXOU J163350.9–474638 varies in intensity on year-long timescales, and with no multi-wavelength counterpart, it could be a distant X-ray binary or possibly a magnetar. CXOU J163355.1–473804 features a helium-like iron line at 6.7 keV and is classified as a nearby cataclysmic variable. Additional surveys are planned for the Norma Arm and Galactic Center, and those NuSTAR observations will benefit from the lessons learned during this pilot study.

The development and initial testing of the Internet Consequences Scales (ICONS).

Abstract: The Internet has become a tool for everyday use in the lives of many people; however, little is known about the consequences of using the Internet on the well-being of individuals. This article describes the development of the Internet Consequences Scale (ICONS), a tool to measure the physical, behavioral, economic, and psychosocial consequences of Internet use. Content validity was established using a panel of experts in Internet communications, and construct validity was established using a confirmatory factor analysis. Reliability of the ICONS was established statistically using Cronbach's alpha. The result was a 44-item tool containing four subscales to measure the consequences of Internet use.

Catholic Schools and Bad Behavior: A Propensity Score Matching Analysis

Abstract: Although there is a sizeable literature on the effect of private school attendance on academic student outcomes, the number of studies that investigate the impact of school sector on non-academic outcomes is limited. Using a rich data set, we analyze the impact of Catholic school attendance on the likelihood that teenagers use or sell drugs, commit property crime, have sex, join gangs, attempt suicide, and run away from home. We employ propensity score matching methods to control for the endogeneity of school choice. Catholic school attendance reduces the propensity to use cocaine and to have sex for female students. However, it increases the propensity to use and sell drugs for male students.

Caching management of mobile DBMS

Abstract: Unlike a traditional client-server network, a mobile computing environment has a very limited bandwidth in a wireless link. Thus, one design goal of caching management in a mobile computing environment is to reduce the use of wireless links. This is the primary objective for this research. Quota data and private data mechanisms are used in our design so that an MU user is able to query and update data from the local DBMS without cache coherence problems. The effect of the two mechanisms is to increase the hit ratio. An agent on an MU along with a program on a base station are used to handle the caching management, including prefetching/hoarding, cache use, cache replacement, and cache-miss handling. The simulation results clearly indicate that our approaches are improvements to the previous research.

Near-infrared spectroscopy of 20 new Chandra sources in the Norma Arm

Abstract: We report on CTIO/NEWFIRM and CTIO/OSIRIS photometric and spectroscopic observations of 20 new X-ray (0.5-10 keV) emitters discovered in the Norma Arm Region Chandra Survey (NARCS). NEWFIRM photometry was obtained to pinpoint the near-infrared counterparts of NARCS sources, while OSIRIS spectroscopy was used to help identify 20 sources with possible high mass X-ray binary properties. We find that (1) two sources are WN8 Wolf-Rayet stars, maybe in colliding wind binaries, part of the massive star cluster Mercer 81; (2) two are emission-line stars, possibly in X-ray binaries, that exhibit near- and mid-infrared excesses either due to free-free emission from the decretion discs of Be stars or warm dust in the stellar winds of peculiar massive stars such as B[e] supergiants or luminous blue variables; (3) one is a B8-A3 IV-V star that could be in a quiescent high mass X-ray binary system; (4) two are cataclysmic variables including one intermediate polar; (5) three may be neutron star symbiotic binaries; (6) five are most likely white dwarf symbiotic binaries; and (7) five exhibit properties more consistent with isolated giant/dwarf stars. The possible detection of one to three high mass X-ray binaries is in good agreement with our predictions. However, our study illustrates the difficulty of clearly differentiating quiescent or intermediate X-ray luminosity systems from isolated massive stars, which may lead to an underestimation of the number of known high mass X-ray binaries.