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Dimitrios Tsolis Spyros Sioutas Michalis Nik Xenos Georgios Styliaras 《Journal of Cultural Heritage》2011,12(4):466
As a general and effective protection measure for copyright violations, which occur with the use of digital technologies including peer-to-peer (P2P) networks, copyright owners from the cultural sector often use Digital Rights Management (DRM) systems and digital watermarking techniques so as to encrypt copyright information to the cultural content. In other cases, copyright owners restrict or even block access to the digital cultural content through the Internet and the P2P infrastructure. This chapter claims that DRM and P2P can be quite complementary. Specifically, a P2P infrastructure is presented which allows broad digital cultural content exchange while on the same time supports copyright protection and management through watermarking technologies for digital images. 相似文献
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Evidence from Project STAR has suggested a considerable advantage of being in small classes in early grades. However, the extra benefits of additional years in small classes have not been discussed in detail. The present study examined the additional effects of being in small classes for more than 1 year. We find that once previous grade achievement and small-class membership are controlled for, small-class effects are typically insignificant except in 1st grade. Findings from longitudinal analyses showed no independent effects of small classes in early grades. Again, the exception was the estimate in 1st-grade mathematics. Thus, there is little evidence about the accumulated benefits of additional years in small classes. If indeed being in small classes for only 1 year is sufficient in early grades, the evidence points to reducing class size in first grade. 相似文献
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Eirini Mergoupi-Savaidou Faidra Papanelopoulou Spyros Tzokas 《Science & Education》2012,21(3):293-310
Based on our research on two Athenian daily newspapers for the first decade of the twentieth century, we present some historiographical
reflections concerning the role of the daily press in the circulation of scientific knowledge, ideas and practices. From the
wealth of material provided, we examine some of the ways in which scientific and technical knowledge was made available to
a wider public and contributed to the creation of a general scientific literacy. Although Greece has never been in the forefront
of scientific and technological research, the vast amount of newspaper articles on science and technology, but also references
to science and technology in other kind of articles, show how discussions on science and technology become part of daily life
in order to serve various agendas. Since newspapers address a very wide and diverse public on a daily basis they become privileged
media not only for understanding the role science and technology played in the formation of modern societies, but also for
examining the values and ideas attached to them and communicated to a wider public. 相似文献
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Marina Palla Despina Potari Panagiotis Spyrou 《International Journal of Science and Mathematics Education》2012,10(5):1023-1045
In this study, we investigate the meaning students attribute to the structure of mathematical induction (MI) and the process of proof construction using mathematical induction in the context of a geometric recursion problem. Two hundred and thirteen 17-year-old students of an upper secondary school in Greece participated in the study. Students’ responses in 3 written tasks and the interviews with 18 of them are analyzed. Though MI is treated operationally in school, the students, when challenged, started to recognize the structural characteristics of MI. In the case of proof construction, we identified 2 types of transition from argumentation to proof, interwoven in the structure of the geometrical pattern. In the first type, MI was applied to the algebraic statement that derived from the direct translation of the geometrical situation. In the second type, MI was embedded functionally in the geometrical structure of the pattern. 相似文献