The Contribution of Educational Sciences to Primary Teacher Training in Greece

In view of the elevation of the primary teachers’ training in Greece to a university level, this paper reports on one aspect of those teachers’ training in the existing primary teachers training institutions, that of the curriculum structure.

The effectiveness of their training was investigated by means of a questionnaire, answered by a sample of 324 experienced primary teachers.

According to the results, the Greek primary teachers seriously question the structure and content of the curriculum in the primary teachers training institutions (the Pedagogical Academies), since it contributes to the training of a type of teacher whom neither they want nor the society needs. For an improved and more effective primary teachers’ training scheme they proposed the focusing of the curriculum on the educational sciences.     

Tracking the singular arc of a continuous bioreactor using sliding mode control

A sliding mode controller is developed for optimal transient operation of a continuous bioreactor. The sliding mode is the singular arc from the solution of an optimal control problem. The proposed controller is applied through simulations to an anaerobic digester and its performance is evaluated in terms of optimality and robustness properties.     

Rapid magnetic heating treatment by highly charged maghemite nanoparticles on Wistar rats exocranial glioma tumors at microliter volume

One of the most significant challenges implementing colloidal magnetic nanoparticles in medicine is the efficient heating of microliter quantities by applying a low frequency alternating magnetic field. The ultimate goal is to accomplish nonsurgically the treatment of millimeter size tumors. Here, we demonstrate the synthesis, characterization, and the in vitro as well as in vivo efficiency of a dextran coated maghemite (γ-Fe₂O₃) ferrofluid with an exceptional response to magnetic heating. The difference to previous synthetic attempts is the high charge of the dextran coating, which according to our study maintains the colloidal stability and good dispersion of the ferrofluid during the magnetic heating stage. Specifically, in vitro 2 μl of the ferrofluid gives an outstanding temperature rise of 33 °C within 10 min, while in vivo treatment, by infusing 150 μl of the ferrofluid in animal model (rat) glioma tumors, causes an impressive cancer tissue dissolution.     

Reciprocal peer assessment as a learning tool for secondary school students in modeling-based learning

The aim of this study was to investigate how reciprocal peer assessment in modeling-based learning can serve as a learning tool for secondary school learners in a physics course. The participants were 22 upper secondary school students from a gymnasium in Switzerland. They were asked to model additive and subtractive color mixing in groups of two, after having completed hands-on experiments in the laboratory. Then, they submitted their models and anonymously assessed the model of another peer group. The students were given a four-point rating scale with pre-specified assessment criteria, while enacting the peer-assessor role. After implementation of the peer assessment, students, as peer assessees, were allowed to revise their models. They were also asked to complete a short questionnaire, reflecting on their revisions. Data were collected by (i) peer-feedback reports, (ii) students’ initial and revised models, (iii) post-instructional interviews with students, and (iv) students’ responses to open-ended questions. The data were analyzed qualitatively and then quantitatively. The results revealed that, after enactment of the peer assessment, students’ revisions of their models reflected a higher level of attainment toward their model-construction practices and a better conceptual understanding of additive and subtractive color mixing. The findings of this study suggest that reciprocal peer assessment, in which students experience both the role of assessor and assessee, facilitates students’ learning in science. Based on our findings, further research directions are suggested with respect to novel approaches to peer assessment for developing students’ modeling competence in science learning.     

A cost-effective wireless network migration planning method supporting high-security enabled railway data communication systems

As a typical railway Cyber-physical System (CPS), radio-based train control systems have been playing an increasingly important role in rail transit. The engaged network, Global System for Mobile Communications for Railway (GSM-R), which is an out-dated wireless communication technology, will be decommissioned due to diminishing support from industry, and a new generation successor, e.g. Long-Term Evolution (LTE), is urgently required to replace the current network. The radio-based train control systems must be safety critical, which relies on a high-security Data Communication System (DCS). In this paper, a novel wireless network migration methodology in DCS is proposed. By using this methodology, the high-security required DCS performance in radio-based train control systems is maintained and the network migration cost, e.g. the used number of base station (BS), is reduced when updating the GSM-R to LTE.     

Social Media Followership as a Predictor of News Website Traffic

ABSTRACT

News organizations increasingly focus their efforts to boost traffic on their websites to grow their share of online advertising. We investigated the relationship between news websites’ traffic ranking and their social media tools of Facebook, Twitter, YouTube and Google Plus. For a year we monitored the followers of all Greek regional newspapers in relation to the traffic on their websites. We continued monitoring for a second year to validate the robustness of the findings and we hereby present results for 86 weeks. Statistical analysis leads to the conclusion that the number of social media subscribers can predict the competitive position of a newspaper in the market based on its website traffic. The effect lasts for a limited period of time, one to three weeks, depending on the specific medium. Importantly, results indicate the potential of developing a prediction model of the website’s traffic, based on the social media metrics of the organization, as a useful tool to increase traffic and revenues from online advertising.     

Secondary School Teachers’ Knowledge and Attitudes Towards Renewable Energy Sources

Investigating knowledge, perceptions as well as attitudes of public that concern various aspects of environmental issues is of high importance for Environmental Education. An integrated understanding of these parameters can properly support the planning of Environmental Education curriculum and relevant educational materials. In this survey we investigated knowledge and attitudes of secondary school teachers in Greece towards renewable energy sources, particularly wind and solar energy systems. A questionnaire with both open and close questions was used as the main methodological instrument. Findings revealed that although teachers were informed about renewable energy sources and well disposed towards these sources, they hardly expressed clear positions regarding several issues about wind and solar energy technologies and farms. Moreover such themes are limited integrated in teaching either as extra curricular educational programs or through the curriculum. These findings cannot confirm that teachers could influence students’ opinion towards renewable energy systems. Thus, authorities should invest more in Environmental Education and relevant Teachers' Education.