Affect state recognition for adaptive human robot interaction in learning environments

Previous studies of robots used in learning environments suggest that the interaction between learner and robot is able to enhance the learning procedure towards a better engagement of the learner. Moreover, intelligent robots can also adapt their behavior during a learning process according to certain criteria resulting in increasing cognitive learning gains. Motivated by these results, we propose a novel Human Robot Interaction framework where the robot adjusts its behavior to the affect state of the learner. Our framework uses the theory of flow to label different affect states (i.e., engagement, boredom and frustration) and adapt the robot's actions. Based on the automatic recognition of these states, through visual cues, our method adapt the learning actions taking place at this moment and performed by the robot. This results in keeping the learner at most times engaged in the learning process. In order to recognizing the affect state of the user a two step approach is followed. Initially we recognize the facial expressions of the learner and therefore we map these to an affect state. Our algorithm perform well even in situations where the environment is noisy due to the presence of more than one person and/or situations where the face is partially occluded

Improving the new product/service introduction process by the application of system dynamics

The development and marketing of new products and services are amongst the most powerful weapons that organisations can'use in order to survive and prosper under turbulent global market conditions. The successful introduction of a new product or service can assist an organisation to remain competitive by being able to sufficiently address the continuously changing market requirements. Therefore, the process of New Product / Service Introduction (NP/SI) constitutes a crucial activity for every organisation. In an environment of ever shortening product life cycles, increased customer expectation, technology advancements and increased market competition, the only factor that remains constant within a modem manufacturing operation is change. Such changes are ultimately reflected in the products and the manufacturing processes. One particular type of change apparent within a manufacturing or assembly environment is engineering change (EQ. The changes or modifications in forms, fits, materials, dimensions, functions, etc. of a product or component are usually referred to as ECs. The aims of this thesis were fulfilled by using the technique of System Dynamics (SD) in order to model and simulate the generic structure of the NP/Sl process and to identify ways to improve it. The results of the simulation were also used for developing an Engineering Change Management System which was then modelled by using the same technique of SD. In this attempt, two Greek organisations collaborated by providing data and information in order to investigate the existence of a cost-time-quality relationship throughout the NP/SI process

Production and Distribution of Glass Objects in Late Antique Thessaloniki (3rd-7th c. A.D.)

The 20th c. excavations in Thessaloniki yielded very huge amounts of various glass finds. The aim of this paper is to replace these objects within the commercial and economic frame of Late Antiquity. They attest the importance of Thessaloniki’s harbour, where arrived goods from all the Eastern Mediterranean. Imported glass artefacts apparently were used as prototypes for a local production. Few glass workshops are documented by excavations and commented here from the topographical and technological point of view: they are replaced in the typology of workshops known from other Mediterranean towns and their production is analysed (repertoire, origin of the models, diffusion into the nearby Balkan regions). Κατά τις ανασκαφές του 20ου αι. στη Θεσσαλονίκη αποκαλύφθηκε σημαντικός αριθμός γυάλινων ευρημάτων πάσης φύσεως. Τα ευρήματα αυτά και η ένταξή τους στα γενικότερα εμπορικά, οικονομικά τεκταινόμενα της 'ϒστερης Αρχαιότητας αποτελούν το θέμα της παρούσας τοποθέτησης. Τα αντικείμενα αυτά μαρτυρούν την σπουδαιότητα του λιμανιού της πόλης, στο οποίο έφταναν εμπορεύματα από ολόκληρη την ανατολική Μεσόγειο και τα οποία, όπως φαίνεται, αποτέλεσαν τα πρότυπα της τοπικής παραγωγής. Ακόμη, παρουσιάζονται τα τοπικά υαλουργεία, που εντοπίστηκαν ανασκαφικά, εξετάζονται με βάση τα χωροταξικά και τεχνολογικά στοιχεία και εντάσσονται στις αντίστοιχες ομάδες υαλουργείων, γνωστών από άλλες πόλεις της Μεσογείου. Τέλος, τύποι αγγείων που βρέθηκαν στις ανασκαφές των υαλουργείων, αλλά και άλλοι που επιχωριάζουν στη Θεσσαλονίκη εξετάζονται ως πιθανά τοπικά προϊόντα, αναζητούνται τα πρότυπά τους και η διάδοσή τους στις κοντινές βαλκανικές περιοχές

The influence of thermal treatments under hydrostatic pressure prior to irradiation on the annealing characteristics of the VO defect in Si

Cz-Si samples, initially subjected to thermal treatments under high hydrostatic pressure, were subsequently irradiated by fast neutrons. This paper describes a series of infrared spectroscopy measurements that enabled us to determine the effect of the pre-treatments on the annealing characteristics of the VO defect in Si. We found that the activation energies of the two main annealing reactions: VO + Oi → VO2 and VO + SiI → Oi that the defect participates, are comparatively smaller than those of initially untreated samples, correspondingly. We argue that the pre-treatments reduce the potential barrier for the migration of the VO defect (VO + Oi → VO2) and also reduces the binding energy of the SiI's, bound at large defect clusters (VO + SiI → Oi). © 2008 Elsevier B.V. All rights reserved

Marques sur verre découvertes en Grèce :addenda (Thessalonique, Corinthe, Itanos, Érétrie, Olympie et Lousoi)

info:eu-repo/semantics/publishe

Infrared spectroscopy studies of localized vibrations in neutron irradiated silicon

We investigate neutron irradiation-induced defects in p-type Czochralski silicon (Cz–Si) subjected initially to heat treatments under high hydrostatic pressure (HTHP), by means of infrared spectroscopy (IR). A pair of bands at 592 and 883 cm−1 arises in the spectra immediately after irradiation and disappears upon isochronal annealing just below 350 °C in as-grown Si, although they disappear at a smaller temperature ~ 280 °C in the HTHP treated Si. Another pair of bands at 535 and 556 cm−1 arises in the spectra at ~ 320 °C and disappears at ~ 430 °C in as-grown Si, although they show a shift in their thermal stability of ~ 50 °C towards lower temperatures in HTHP Si. The activation energies characterizing their annihilation were found smaller in the HTHP Si, for each one of the four bands correspondingly. It is argued that the applied hydrostatic pressure affects the annealing behavior of the bands promoting their annihilation. From the LVM frequency values, the temperature range they appear and their annealing behavior we tentatively correlate them with structures involving self-interstitial clusters, presumably perturbed by an impurity atom. Four other bands at 562, 642, 654 and 678 cm−1 show similar thermal stability arising in the spectra in the course of the isochronal annealing at ~ 250 °C and disappearing at ~ 400 °C, both in as-grown and in HTHP Si. However, the changes exhibited in the values of the activation energies of the bands between the HTHP and the as-grown Si, suggest that may not all of them have exactly the same origin, at least the 678 cm−1 band. The origin of the above family of bands is discussed in regards with previous works reported in the literature. Connection with complexes comprising boron atoms and self interstitials, in short (Bn–SiIm), was considered. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

Di-interstitial defect in silicon revisited

Infrared spectroscopy was used to study the defect spectrum of Cz-Si samples following fast neutron irradiation. We mainly focus on the band at 533 cm-1, which disappears from the spectra at ∼170 °C, exhibiting similar thermal stability with the Si-P6 electron paramagnetic resonance (EPR) spectrum previously correlated with the di-interstitial defect. The suggested structural model of this defect comprises of two self-interstitial atoms located symmetrically around a lattice site Si atom. The band anneals out following a first-order kinetics with an activation energy of 0.88 ± 0.3 eV. This value does not deviate considerably from previously quoted experimental and theoretical values for the di-interstitial defect. The present results indicate that the 533 cm-1 IR band originates from the same structure as that of the Si-P6 EPR spectrum. © 2013 AIP Publishing LLC