233 research outputs found
Flexibility Aggregation of Temporally Coupled Resources in Real Time Balancing Markets Using Machine Learning
In modern power systems with high penetration of renewable energy sources, the flexibility provided by distributed energy resources is becoming invaluable. Demand aggregators offer balancing energy in the real-time balancing market on behalf of flexible resources. A challenging task is the design of the offering strategy of an aggregator. In particular, it is difficult to capture the flexibility cost of a portfolio of flexibility assets within a price-quantity offer, since the costs and constraints of flexibility resources exhibit inter-temporal dependencies. In this article, we propose a generic method for constructing aggregated balancing energy offers that best represent the portfolio's actual flexibility costs, while accounting for uncertainty in future timeslots. For the case study presented, we use offline simulations to train and compare different machine learning (ML) algorithms that receive the information about the state of the flexible resources and calculate the aggregator's offer. Once trained, the ML algorithms can make fast decisions about the portfolio's balancing energy offer in the real-time balancing market. Our simulations show that the proposed method performs reliably towards capturing the flexibility of the Aggregator's portfolio and minimizing the aggregator's imbalances.</p
Quantum and classical optical channels Coexistence in optical Access Networks
Η διατριβή αυτή ερευνά τη συνύπαρξη της Διανομής Κβαντικών Κλειδιών (QKD) με κλασικά κανάλια σε οπτικά δίκτυα πρόσβασης. Η εισαγωγή παρέχει μια επισκόπηση του θέματος και στη συνέχεια ακολουθεί μια σύνοψη των αρχών της κβαντικής μηχανικής και των διαδικασιών που εφαρμόζονται στην κβαντική διανομή κλειδιών. Συζητούνται κάποια πρωτόκολλα QKD, συμπεριλαμβανομένων των ΒΒ84 και ΒΒ84 με decoy καταστάσεις. Η διατριβή εξετάζει επίσης την επίδραση μη γραμμικών φαινομένων, όπως η σκέδαση Raman, ο θόρυβος που προκαλείται απο την παρουσία πολλαπλών κυμάτων , καθώς και γραμμικών φαινομένων, όπως η ανάκλαση Rayleigh και η χρωματική διάσπορά. Μετά την ανάλυση των θεωρητικών προαπαιτούμενων, παρέχεται μια σύνοψη των προηγούμενων ερευνών για τη συνύπαρξη του QKD με κλασικά κανάλια. Επιπλέον, περιλαμβάνεται η πειραματική διαδικασία που αποτελείται από δύο μέρη.
Το πρώτο μέρος περιλαμβάνει μια έρευνα που γίνεται στο εργαστήριο οπτικής. Πιο συγκεκριμένα μελετώνται οι αλληλεπιδράσεων όταν δύο ζεύγη μηχανημάτων Toshiba που υλοποιούν το πρωτόκολλο BB84 με decoy states τοπόθετούνται σε φορά αντίθετης διάδοσης καθώς και η συνύπαρξη αυτής της τοπολογίας με κλασσικά κανάλια. Τέλος, το δεύτερο μέρος παρουσιάζει την πρακτική εφαρμογή της συνύπαρξης των κβαντικών καναλιών θέτοντας σε λειτουργία τον εξοπλισμό της Toshiba στην προσομοίωση του GPON δικτύου της COSMOTE που βρίσκεται στο OTE Academy.This master thesis explores the coexistence of Quantum Key Distribution (QKD) with
classical channels in optical access networks. The introduction provides an overview of the
topic, followed by an overview of the principles of quantum mechanics and QKD procedures. Various QKD protocols, including BB84and BB84 Decoy State are discussed. The thesis also investigates the impact of nonlinear effects such as Raman scattering and four-wave mixing, as well as linear effects like Rayleigh back-scattering and chromatic dispersion on the coexistence of QKD with classical channels. After having discussed the theoretical background the thesis provides a synopsis of prior research on the coexistence of QKD with classical channels. Furthermore there is an experimental procedure which consists of two parts. The first part involves an investigation of counter-propagating interactions in quantum communications using two pairs of Toshiba machines which implement the BB84 protocol with decoy states and also the coexistence of counter-propagating interactions with classical channels . Finally the second part presents the practical deployment of QKD coexistence over GPON replica located at OTE Academy
Compulsivity in Alcohol Use Disorder and Obsessive Compulsive Disorder: Implications for Neuromodulation
Alcohol use Disorder (AUD) is one of the leading causes of morbidity and mortality worldwide. The progression of the disorder is associated with the development of compulsive alcohol use, which in turn contributes to the high relapse rate and poor longer term functioning reported in most patients, even with treatment. While the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) defines AUD by a cluster of symptoms, parsing its heterogeneous phenotype by domains of behavior such as compulsivity may be a critical step to improve outcomes of this condition. Still, neurobiological underpinnings of compulsivity need to be fully elucidated in AUD in order to better design targeted treatment strategies. In this manuscript, we review and discuss findings supporting common mechanisms between AUD and OCD, dissecting the construct of compulsivity and focusing specifically on characteristic disruptions in habit learning and cognitive control in the two disorders. Finally, neuromodulatory interventions are proposed as a probe to test compulsivity as key pathophysiologic feature of AUD, and as a potential therapy for the subgroup of individuals with compulsive alcohol use, i.e., the more resistant stage of the disorder. This transdiagnostic approach may help to destigmatize the disorder, and suggest potential treatment targets across different conditions
The organisation of an educational program for specialists in clinical chemistry by the Greek Society of Clinical Chemistry-Clinical Biochemistry
In Greece, there is no officially organized training in clinical chemistry for scientists. The Greek Society of Clinical Chemistry-Clinical Biochemistry decided to organize an intensive educational prog-ram of 18 seminars on clinical chemistry content as it is described in the EC4 Syllabus.
The duration of each seminar was about 6 hours and consisted of 6 to 9 lectures. At the end of each seminar there was a voluntary written examination, comprised of 24 multiple choice questions. Suc-cessful completion of the Educational program was leading to a Certificate of Competence.
Two cycles of the 18 seminars were performed: 1st cycle from October 2003 to December 2005 and 2nd cycle from March 2005 to October 2007. One hundred eighty nine colleagues was the mean at-tendance per seminar for the seminars of the 1st cycle and 38 colleagues for the seminars of the 2nd cycle. The mean participation to the examination for each seminar was almost 80% for the 1st cycle and 68% for the 2nd cycle. More than 80% of the participants performed Good or Very good in the examination in both cycles.
It is estimated that more than 40% of the scientists who practice Clinical Chemistry in Greece, partici-pated to this educational activity. This program is now provided as an e-learning application, and it is open for all scientists who want to follow the discipline of clinical chemistry
The organisation of an educational program for specialists in clinical chemistry by the Greek Society of Clinical Chemistry-Clinical Biochemistry
In Greece, there is no officially organized training in clinical chemistry for scientists. The Greek Society of Clinical Chemistry-Clinical Biochemistry decided to organize an intensive educational prog-ram of 18 seminars on clinical chemistry content as it is described in the EC4 Syllabus.
The duration of each seminar was about 6 hours and consisted of 6 to 9 lectures. At the end of each seminar there was a voluntary written examination, comprised of 24 multiple choice questions. Suc-cessful completion of the Educational program was leading to a Certificate of Competence.
Two cycles of the 18 seminars were performed: 1st cycle from October 2003 to December 2005 and 2nd cycle from March 2005 to October 2007. One hundred eighty nine colleagues was the mean at-tendance per seminar for the seminars of the 1st cycle and 38 colleagues for the seminars of the 2nd cycle. The mean participation to the examination for each seminar was almost 80% for the 1st cycle and 68% for the 2nd cycle. More than 80% of the participants performed Good or Very good in the examination in both cycles.
It is estimated that more than 40% of the scientists who practice Clinical Chemistry in Greece, partici-pated to this educational activity. This program is now provided as an e-learning application, and it is open for all scientists who want to follow the discipline of clinical chemistry
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