6,084 research outputs found

    Towards Security Requirements in Online Summative Assessments

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    Confidentiality, integrity and availability (C-I-A) are the security requirements fundamental to any computer system. Similarly, the hardware, software and data are important critical assets. These two components of a computer security framework are entwined; such that a compromise in the C-I-A requirements may lead to a compromise of the critical assets. The C-I-A requirements and the critical assets of a computer system are well researched areas; however they may be insufficient to define the needs of a summative e-assessment system. In this paper, we do not discard the existing components; rather we propose security requirements and related components that are specific to summative e-assessment systems

    Towards Security Goals in Summative E-Assessment Security

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    The general security goals of a computer system are known to include confidentiality, integrity and availability (C-I-A) which prevent critical assets from potential threats. The C-I-A security goals are well researched areas; however they may be insufficient to address all the needs of the summative e-assessment. In this paper, we do not discard the fundamental C-I-A security goals; rather we define security goals which are specific to summative e-assessment security

    Solution to the differential equation for combined radiative and convective cooling for a heated sphere

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    A solution is presented for the differential equation relating the combined effects of radiative and forced convective cooling for a heated sphere. The equation has the form where T and t are the variables temperature and time, respectively, and K sub o, T sub o, and H are constants. The solution can be used as a guideline for the design and understanding of space processing phenomena

    Spectral Properties From Lyman-alpha to H-alpha For An Essentially Complete Sample of Quasars I: Data

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    We have obtained quasi-simultaneous ultraviolet-optical spectra for 22 out of 23 quasars in the complete PG-X-ray sample with redshift, z<0.4, and M_B<-23. The spectra cover rest-frame wavelengths from at least Lyman-alpha to H-alpha. Here we provide a detailed description of the data, including careful spectrophotometry and redshift determination. We also present direct measurements of the continua, strong emission lines and features, including Lyman-alpha, SiIV+OIV], CIV, CIII], SiIII], MgII, H-beta, [OIII], He5876+NaI5890,5896, H-alpha, and blended iron emission in the UV and optical. The widths, asymmetries and velocity shifts of profiles of strong emission lines show that CIV and Lyman-alpha are very different from H-beta and H-alpha. This suggests that the motion of the broad line region is related to the ionization structure, but the data appears not agree with the radially stratified ionization structure supported by reverberation mapping studies, and therefore suggest that outflows contribute additional velocity components to the broad emission line profiles.Comment: 42 pages, 10 figures, 13 tables. Accepted by AJ. Supplemental figures not included. Full version available at http://physics.uwyo.edu/~shang/pgxpaper/ShangPaper.pd

    IECM calibration and data reduction requirements

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    The induced environment contamination monitor (IECM) tape recorder format, as it relates to the ouput of meaningful data from the IECM instrument, is explained. Eight-bit words (or bytes) generate numbers that represent voltage levels of electronic detection probes for each experiment. This information is amalgamated by the IECM Data Acquisition and Control System (DACS). In some cases bits represent certain status situations concerning an experiment, such as whether a valve is opened or closed. Voltages are transformed into meaningful physical phenomena through equations of calibration. Data formats and plots are generated as requested for each IECM experimenter
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