175 research outputs found

    ΤHE IMPACT OF COGNITIVE DIMENSION OF TAM-PERCEIVED USEFULNESS AND PERCEIVED EASE OF USE IN TEACHERS’ ATTITUDES TOWARDS ICT’S INTEGRATION IN TEACHING ANCIENT GREEK LANGUAGE IN LOWER SECONDARY SCHOOL: THE CASE OF GREECE

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    This study aims to delve deeper into Greek teachers’ attitudes towards the use of ICT in ancient Greek teaching, in Greek public lower secondary schools, representing an attempt to identify the Cognitive Dimension of Greek teachers’ of ancient Greek language (philologists) attitudes. More specifically, the main goal is to examine Perceived Ease of Use and Perceived Usefulness concerning teachers’ of ancient Greek degree of familiarity with ICTs and the degree of effectiveness in ICT’s integration in teaching and learning practice.            As for Perceived Ease of Use this research study investigates, in respect of teachers’ attitudes:a)      ICT’s degree of personal and educational use,b)     Self-perception degree towards ICT’s use, andc)      Degree of ability in ICT’s teaching integration.            As for Perceived Usefulness this study investigates:a)      ICT’s usefulness degree in achieving learning objectives,b)     Usefulness degree in teaching application of ICT, andc)      ICT’s effectiveness degree as for teachers’ role.            Broadly speaking, the research findings reveal that teachers of ancient Greek, use ICTs to do their lesson preparation and planning, but they are not used to integrating technology in teaching practices.            Yet, Greek teachers of ancient Greek language consider -as important barrier/factor to use ICT in teaching and learning process- their lack of effective training in ICT’s teaching use. As a result, they show low self-perception degree -as for ICT’s use- and become more and more reluctant to adopt new technologies in teaching and learning procedure. Moreover, the findings stress that Greek philologists firmly believe that ICT can be used as an innovative tool of teaching and learning procedure, motivating teachers and increasing their interest in teaching approach. However, New Educational Technology is not applied in teaching practice and teachers of ancient Greek language -denied to ‘escape’ from traditional ways of teaching- prefer conventional/traditional teaching practices in ICT’s use to modern/contemporary teaching methods, achieving mainly cognitive goals.            To sum up: a) gender, b) years of experience in teaching, c) specific knowledge in teaching ancient Greek language with ICT, and d) appropriate in-service training on ICTs have a significant impact on teachers’ of ancient Greek attitudes, regarding whether or not ICT’ s use enhance:a)      traditional teaching style,b)     linguistic literacy,c)      critical literacy,d)     sociocultural literacy.  Article visualizations

    USING ELECTRONIC TEXT CORPORA IN TEACHING ANCIENT GREEK: A VOCABULARY TEACHING INTERVENTION IMPLEMENTED IN THE ANCIENT GREEK COURSE IN THE 3RD GRADE OF LOWER SECONDARY SCHOOL

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    The present didactic intervention aims to highlight the effective use of Electronic Text Corpora in the teaching approach of the Ancient Greek course. In particular, the teaching of a unit found in the school textbook of the 3rd grade of lower secondary school is examined at its vocabulary and semantic level, using the Digital Resources (http://www.greek-language.gr/digitalResources/) for the Greek language and the Portal for the Greek language (http://www.greek-language.gr/greekLang/index.html). Using Electronic Text Corpora, students take part in the learning process through a critical way by building an interactive and communicative learning environment. The dynamic use of ETC in the teaching process can constitute the bridge between traditional and new literacy in the Information Society and Communication. Article visualizations

    Accuracy of site coordinates obtainable by a mobile lunar laser station

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    The accuracy with which a mobile lunar laser station can be located was the subject of a modeling study. The influence of the number and accuracy of fixed lunar ranging stations, the uncertainty in polar motion, and data loss due to weather and similar factors were considered, and the results are given in a cartographic form. In general, all three coordinates (for coordinates to latitude + or - 60 deg) were determined to better than the pole uncertainty, given three or more fixed sites and reasonable weather. This result indicates that one or more mobile stations would be suitable for the study of geotectonics

    Frame-based modeling of H.264 constrained videoconference traffic over an IP commercial platform

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    High-frequency modes in solar-like stars

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    p-mode oscillations in solar-like stars are excited by the outer convection zone in these stars and reflected close to the surface. The p-modes are trapped inside an acoustic cavity, but the modes only stay trapped up to a given frequency (known as the acoustic cut-off frequency) as modes with larger frequencies are generally not reflected at the surface. This means that modes with frequency larger than the acoustic cut-off frequency must be traveling waves. The high-frequency modes may provide information about the physics in the outer layers of the stars and the excitation source and are therefore highly interesting as it is the estimation of these two phenomena that causes some of the largest uncertainties when calculating stellar oscillations. High-frequency modes have been detected in the Sun, beta Hydri and in alpha Cen A & B by smoothing the so-called echelle diagram and the large frequency separation as a function of frequency have been estimated. The large frequency separation has been compared with a simple model of the acoustic cavity which suggests that the reflectivity of the photosphere is larger at high frequency than predicted by standard models of the solar atmosphere and that the depth of the excitation source is larger than what has been estimated by other models and might depend on the order n and degree l of the modes.Comment: 11 pages, 5 figures. Accepted for publication in MNRA

    The pulsating DA white dwarf star EC 14012-1446: results from four epochs of time-resolved photometry

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    The pulsating DA white dwarfs are the coolest degenerate stars that undergo self-driven oscillations. Understanding their interior structure will help to understand the previous evolution of the star. To this end, we report the analysis of more than 200 h of time-resolved CCD photometry of the pulsating DA white dwarf star EC 14012-1446 acquired during four observing epochs in three different years, including a coordinated three-site campaign. A total of 19 independent frequencies in the star's light variations together with 148 combination signals up to fifth order could be detected. We are unable to obtain the period spacing of the normal modes and therefore a mass estimate of the star, but we infer a fairly short rotation period of 0.61 +/- 0.03 d, assuming the rotationally split modes are l=1. The pulsation modes of the star undergo amplitude and frequency variations, in the sense that modes with higher radial overtone show more pronounced variability and that amplitude changes are always accompanied by frequency variations. Most of the second-order combination frequencies detected have amplitudes that are a function of their parent mode amplitudes, but we found a few cases of possible resonantly excited modes. We point out the complications in the analysis and interpretation of data sets of pulsating white dwarfs that are affected by combination frequencies of the form f_A+f_B-f_C intruding into the frequency range of the independent modes.Comment: 14 pages, 6 figures, 6 tables. MNRAS, in pres

    Asteroseismology with the WIRE satellite. I. Combining Ground- and Space-based Photometry of the Delta Scuti Star Epsilon Cephei

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    We have analysed ground-based multi-colour Stromgren photometry and single-filter photometry from the star tracker on the WIRE satellite of the delta scuti star Epsilon Cephei. The ground-based data set consists of 16 nights of data collected over 164 days, while the satellite data are nearly continuous coverage of the star during 14 days. The spectral window and noise level of the satellite data are superior to the ground-based data and this data set is used to locate the frequencies. However, we can use the ground-based data to improve the accuracy of the frequencies due to the much longer time baseline. We detect 26 oscillation frequencies in the WIRE data set, but only some of these can be seen clearly in the ground-based data. We have used the multi-colour ground-based photometry to determine amplitude and phase differences in the Stromgren b-y colour and the y filter in an attempt to identify the radial degree of the oscillation frequencies. We conclude that the accuracies of the amplitudes and phases are not sufficient to constrain theoretical models of Epsilon Cephei. We find no evidence for rotational splitting or the large separation among the frequencies detected in the WIRE data set. To be able to identify oscillation frequencies in delta scuti stars with the method we have applied, it is crucial to obtain more complete coverage from multi-site campaigns with a long time baseline and in multiple filters. This is important when planning photometric and spectroscopic ground-based support for future satellite missions like COROT and KEPLER.Comment: 13 pages, 12 figures, 4 tables. Fig. 4 reduced in quality. Accepted by A&

    The CoRoT star 105288363: strong cycle to cycle changes of the Blazhko modulation

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    We present the analysis of the CoRoT star 105288363, a new Blazhko RR Lyrae star of type RRab (f0 = 1.7623 c/d), observed with the CoRoT space craft during the second long run in direction of the galactic center (LRc02, time base 145 d). The CoRoT data are characterized by an excellent time sampling and a low noise amplitude of 0.07 mmag in the 2-12 c/d range and allow us to study not only the fine details of the variability of the star but also long-term changes in the pulsation behaviour and the stability of the Blazhko cycle. We use, among other methods, standard Fourier analysis techniques and O-C diagrams to investigate the pulsational behavior of the Blazhko star 105288363. In addition to the frequency pattern expected for a Blazhko RR Lyrae star, we find an independent mode (f1 = 2.984 c/d) showing a f0/f1 ratio of 0.59 which is similar to that observed in other Blazhko RR Lyrae stars. The bump and hump phenomena are also analysed, with their variations over the Blazhko cycle. We carefully investigated the strong cycle-to-cycle changes in the Blazhko modulation (PB = 35.6 d), which seem to happen independently and partly diametrically in the amplitude and the phase modulation. Furthermore, the phasing between the two types of modulation is found to change during the course of the observations.Comment: 15 pages, 8 figures, accepted for publication in MNRA

    Confirmation of simultaneous p and g mode excitation in HD 8801 and Gamma Peg from time-resolved multicolour photometry of six candidate "hybrid" pulsators

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    We carried out a multi-colour time-series photometric study of six stars claimed as "hybrid" p and g mode pulsators in the literature. Gamma Peg was confirmed to show short-period oscillations of the Beta Cep type and simultaneous long-period pulsations typical of Slowly Pulsating B (SPB) stars. From the measured amplitude ratios in the Stromgren uvy passbands, the stronger of the two short period pulsation modes was identified as radial; the second is l=1. Three of the four SPB-type modes are most likely l=1 or 2. Comparison with theoretical model calculations suggests that Gamma Peg is either an 8.5 solar mass radial fundamental mode pulsator or a 9.6 solar mass first radial overtone pulsator. HD 8801 was corroborated as a "hybrid" Delta Sct Gamma Dor star; four pulsation modes of the Gamma Dor type were detected, and two modes of the Delta Sct type were confirmed. Two pulsational signals between the frequency domains of these two known classes of variables were confirmed and another was newly detected. These are either previously unknown types of pulsation, or do not originate from HD 8801. The O-type star HD 13745 showed small-amplitude slow variability on a time scale of 3.2 days. This object may be related to the suspected new type of supergiant SPB stars, but a rotational origin of its light variations cannot be ruled out at this point. 53 Psc is an SPB star for which two pulsation frequencies were determined and identified with low spherical degree. The behaviour of 53 Ari and Iota Her is consistent with non-variability during our observations, and we could not confirm light variations of the comparison star 34 Psc previously suspected. The use of signal-to-noise criteria in the analysis of data sets with strong aliasing is critically discussed.Comment: 14 pages, 10 figures, accepted by MNRA

    Close binary stars in the solar-age Galactic open cluster M67

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    We present multi-colour time-series CCD photometry of the solar-age galactic open cluster M67 (NGC 2682). About 3600 frames spread over 28 nights were obtained with the 1.5 m Russian-Turkish and 1.2 m Mercator telescopes. High-precision observations of the close binary stars AH Cnc, EV Cnc, ES Cnc, the δ\delta Scuti type systems EX Cnc and EW Cnc, and some long-period variables belonging to M67 are presented. Three full multi-colour light curves of the overcontact binary AH Cnc were obtained during three observing seasons. Likewise we gathered three light curves of EV Cnc, an EB-type binary, and two light curves of ES Cnc, a blue straggler binary. Parts of the light change of long-term variables S1024, S1040, S1045, S1063, S1242, and S1264 are obtained. Period variation analysis of AH Cnc, EV Cnc, and ES Cnc were done using all times of mid-eclipse available in the literature and those obtained in this study. In addition, we analyzed multi-colour light curves of the close binaries and also determined new frequencies for the δ\delta Scuti systems. The physical parameters of the close binary stars were determined with simultaneous solutions of multi-colour light and radial velocity curves. Finally we determined the distance of M67 as 857(33) pc via binary star parameters, which is consistent with an independent method from earlier studies.Comment: 12 pages, 9 Figures, 13 Table
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