M-Learning: A Psychometric Study of the Mobile Learning Perception Scale

The purpose of this research was to evaluate the psychometric properties of Uzunboylu and Ozdamli (2011) Mobile Learning Perception Scale (MLPS) in order to determine whether it was an acceptable instrument to measure U.S. teachers\u27 perception of mobile learning (m-learning) in the classroom. A second purpose was to determine if relationships existed between teachers\u27 perceptions of m-learning in comparison to school level and the teachers self-reported technology skill level. Two hundred twenty-four teachers from 16 public schools in Pennsylvania participated in this study for a response rate of43%. Factor analysis confirmed a similar three factor structure with K-12 teachers with high reliability to that of the secondary teachers of Uzunboylu and Ozdamli\u27s study. Significant relationships were found for both school level and self-report skill level. High school teachers\u27 perceptions of m-learning were found to be significantly lower for Factor 1 compared to the elementary teachers\u27 perceptions and the overall school level mean (elementary, middle and high school) was 3.62 on a 1-5 Likert scale. For self-reported technology skill level, the teachers at the proficient/expert level rated items significantly higher for both Factor 1 and Factor 3 compared to the teachers in the novice/beginner level. Chi square analysis found 13 total significant relationships between school level (5) and skill level (8) and reported usage of specific technologies in the classroom on a weekly basis. The findings suggested that, although school level and self-reported skill level are related to teachers\u27 m-learning attitudes and use of specific technologies, other variables should be tested as well such student motivation to use technology, teachers\u27 beliefs about change, and teachers\u27 experience with professional development about technology use. It was suggested that strategic planning in technology implementation, targeted professional training and challenging teachers\u27 beliefs are needed for fuller acceptance of m-learning

Program representation size in an intermediate language with intersection and union types

The CIL compiler for core Standard ML compiles whole programs using a novel typed intermediate language (TIL) with intersection and union types and flow labels on both terms and types. The CIL term representation duplicates portions of the program where intersection types are introduced and union types are eliminated. This duplication makes it easier to represent type information and to introduce customized data representations. However, duplication incurs compile-time space costs that are potentially much greater than are incurred in TILs employing type-level abstraction or quantification. In this paper, we present empirical data on the compile-time space costs of using CIL as an intermediate language. The data shows that these costs can be made tractable by using sufficiently fine-grained flow analyses together with standard hash-consing techniques. The data also suggests that non-duplicating formulations of intersection (and union) types would not achieve significantly better space complexity.National Science Foundation (CCR-9417382, CISE/CCR ESS 9806747); Sun grant (EDUD-7826-990410-US); Faculty Fellowship of the Carroll School of Management, Boston College; U.K. Engineering and Physical Sciences Research Council (GR/L 36963, GR/L 15685

Local u'g'r'i'z' Standard Stars in the Chandra Deep Field-South

Because several observing programs are underway in various spectral regimes to explore the Chandra Deep Field South (CDF-S), the value of local photometric standards is obvious. As part of an NOAO Surveys Program to establish u'g'r'i'z' standard stars in the southern hemisphere, we have observed the central region of the CDF-S to create local standards for use by other investigators using these filters. As a courtesy, we present the CDF-S standards to the public now, although the main program will not finish until mid-2005.Comment: Accepted by AJ (scheduled for October 2003 issue). 26 pages, 5 tables, 5 figures. High resolution version of Figure 7 available at http://home.fnal.gov/~dtucker/Southern_ugriz/index.htm

Improved u′g′r′i′z′u'g'r'i'z' to UBVRCICUBVR_CI_C Transformation Equations for Main Sequence Stars

We report improved transformation equations between the $u'g'r'i'z'$ and $UBVR_CI_C$ photometric systems. Although the details of the transformations depend on luminosity class, we find a typical rms scatter on the order of 0.001 magnitude if the sample is limited to main sequence stars. Furthermore, we find an accurate transformation requires complex, multi-color dependencies for the bluer bandpasses. Results for giant stars will be reported in a subsequent paper.Comment: 7 pages, 8 figure

LP 400-22, A very low-mass and high-velocity white dwarf

We report the identification of LP 400-22 (WD 2234+222) as a very low-mass and high-velocity white dwarf. The ultraviolet GALEX and optical photometric colors and a spectral line analysis of LP 400-22 show this star to have an effective temperature of 11080+/-140 K and a surface gravity of log g = 6.32+/-0.08. Therefore, this is a helium core white dwarf with a mass of 0.17 M_solar. The tangential velocity of this white dwarf is 414+/-43 km/s, making it one of the fastest moving white dwarfs known. We discuss probable evolutionary scenarios for this remarkable object.Comment: accepted for publication in ApJ Letters, made minor correction

Self-reported health-related quality of life in persons with HIV infection: results from a multi-site interview project

BACKGROUND: To examine demographic and behavioral associations with self-reported health-related quality of life (HRQOL) among persons with HIV infection or AIDS. METHODS: Analysis of interviews with persons ≥ 18 years of age reported through routine disease surveillance with HIV infection or AIDS to nine state and local health departments from January 1995 through December 1996. Scales were constructed from validated measures of HRQOL, and mean scores were calculated (lower scores signified poorer HRQOL). Measures of HRQOL included Overall Health, Pain, Physical Functioning, Role Functioning, Social Functioning, Mental Health, Energy/Fatigue, and Cognitive Functioning. Differences in HRQOL were examined by various demographic and behavioral factors, including taking antiretroviral medication. RESULTS: HRQOL data were available for 3778 persons. Factors associated with lower HRQOL scores included older age, female sex, black or Hispanic race/ethnicity, injection drug use, lower education and income, no private health insurance, and lower CD4 count. In multivariate analysis, lower CD4 count was the factor most consistently associated with lower HRQOL. Taking antiretroviral medication was not associated with differences in HRQOL regardless of CD4 count. CONCLUSIONS: Perception of HRQOL varied in a population with HIV infection or AIDS. On most HRQOL measures, lower CD4 count was associated with lower HRQOL. Measurement of HRQOL can assist in understanding the long-term effects of disease and treatment on persons with HIV