265 research outputs found
Το ταφικό έθιμο της ανέγερσης τύμβου κατα μήκος της Ιονίας και Αδριατικής ακτής ως πολιτιστικό και κοινωνικό φαινόμενο
This article deals with the two-folded role of the burial custom of tumulus along the Adriatic and Ionian Arc, both as an impressive architectural construction that excels in the surrounding area, as well as a symbolic place of collective memory for the local communities. Initially, the main architectural features –the central burial, the soil and the enclosure– are presented, which, with varied local peculiarities, determine the emergence of the tumulus almost simultaneously in these regions and its evolution in the course of the 3rd and 2nd millennia BC. Furthermore, the article is focused on the chronological and geographical distribution of the tumulus custom starting from the northern Adriatic and ending in the southern part of the Ionian Sea with the scope of unfolding local similarities and differences. The social role of the tumulus as a labour-intensive, enduring and highly visible ancestral monument – signal (sema), is then addressed, via both its topographical correlation to its settlement and the surrounding landscape, and via the ceremonial acts performed in several of them in the study area. Finally, through the choice of selected groups of finds and the adoption of common burial practices, the cultural relations of these regions and the special bond developed between them during the Bronze Age are emerging
Modeling Reader's Emotional State Response on Document's Typographic Elements
We present the results of an experimental study towards modeling the reader's emotional state variations induced by the typographic elements in electronic documents. Based on the dimensional theory of emotions we investigate how typographic elements, like font style (bold, italics, bold-italics) and font (type, size, color and background color), affect the reader's emotional states, namely, Pleasure, Arousal, and Dominance (PAD). An experimental procedure was implemented conforming to International Affective Picture System guidelines and incorporating the Self-Assessment Manikin test. Thirty students participated in the experiment. The stimulus was a short paragraph of text for which any content, emotion, and/or domain dependent information was excluded. The Analysis of Variance revealed the dependency of (a) all the three emotional dimensions on font size and font/background color combinations and (b) the Pleasure dimension on font type and font style. We introduce a set of mapping rules showing how PAD vary on the discrete values of font style and font type elements. Moreover, we introduce a set of equations describing the PAD dimensions' dependency on font size. This novel model can contribute to the automated reader's emotional state extraction in order, for example, to enhance the acoustic rendition of the documents, utilizing text-to-speech synthesis
A novel device for controlling the flow of information based on Weyl fermions and a method for manipulating the spatial distribution of Weyl particles
In this work we propose a novel device for controlling the flow of
information using Weyl fermions. In more detail, based on a previous work of
our group, we show that it is possible to fully control the flow of Weyl
fermions on a sequence of different channels, by applying an electric field
perpendicular to the direction of motion of the particles on each channel. In
this way, we can transmit information, logical bits, depending on the existence
or not of a Weyl current on each channel. We also show that the response time
of this device is exceptionally low, less than 1 ps, for typical values of the
parameters, providing the opportunity to control the flow of information at
extremely high rates, of the order of 100 Pbps. This device also offers
additional advantages, as low power consumption and robustness against
electromagnetic perturbations, and is expected to find important applications
in several fields, as telecommunications, signal processing, classical and
quantum computing, etc. Finally, we demonstrate that Weyl fermions can be
efficiently guided through the proposed device using appropriate magnetic
fields
Emerging Evidence for Neolithic Ithaca
The article presents new evidence for the Neolithic habitation on Ithaca, consisting of ceramic and stone finds, recognised among material from the University of Ioannina excavations at the site of Agios Athanasios-School of Homer in the northwest part of Ithaca, Greece. The new Neolithic site is considered within the wider cultural context of the Ionian Islands, in the late 5th/4th millennium BC. Our current knowledge suggests a permanent Neolithic occupation at the site, as opposed to seasonal occupation or to a special purpose occupation. The Neolithic people at the School of Homer may have been part of a dynamic network of Late/Final Neolithic installations in Western Greece, engaging themselves in inter-regional communal connections along the routes of the most ancient seafaring in the Ionian Sea
Degenerate solutions to the massless Dirac and Weyl equations and a proposed method for controlling the quantum state of Weyl particles
In a recent work we have shown that all solutions to the Weyl equation and a
special class of solutions to the Dirac equation are degenerate, in the sense
that they remain unaltered under the influence of a wide variety of different
electromagnetic fields. In the present article our previous work is
significantly extended, providing a wide class of degenerate solutions to the
Dirac equation for massless particles. The electromagnetic fields corresponding
to these solutions are calculated, giving also some examples regarding both
spatially constant electromagnetic fields and electromagnetic waves. Further,
some general forms of solutions to the Weyl equation are presented and the
corresponding electromagnetic fields are calculated. Based on these results, a
method for fully controlling the quantum state of Weyl particles through
appropriate electromagnetic fields is proposed. Finally, the transition from
degenerate to non-degenerate solutions as the particles acquire mass is
discussed.Comment: Keywords: Dirac equation, Weyl equation, Degenerate solutions,
Massless particles, Electromagnetic 4-potentials, Electromagnetic fields,
Electromagnetic waves, Nearly degenerate solution
A general method for obtaining degenerate solutions to the Dirac and Weyl equations and a discussion on the experimental detection of degenerate states
In this work we describe a general method for obtaining degenerate solutions
to the Dirac equation, corresponding to an infinite number of electromagnetic
4-potentials and fields, which are explicitly calculated. In more detail, using
four arbitrary real functions, one can automatically construct a spinor which
is solution to the Dirac equation for an infinite number of electromagnetic
4-potentials, defined by those functions. An interesting characteristic of
these solutions is that, in the case of Dirac particles with non-zero mass, the
degenerate spinors should be localized, both in space and time. Our method is
also extended to the cases of massless Dirac and Weyl particles, where the
localization of the spinors is no longer required. Finally, we propose two
experimental methods for detecting the presence of degenerate states.Comment: In this version of the article we have added a discussion on the
experimental detection of degenerate states, proposing two techniques based
on electrical and optical measurement
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