30 research outputs found
Performance optimization of next-generation data-driven wireless networks : a machine learning approach
No full textEnd-to-end learning from spectrum data : a deep learning approach for wireless signal identification in spectrum monitoring applications
No full textThis paper presents end-to-end learning from spectrum data an umbrella term for new sophisticated wireless signal identification approaches in spectrum monitoring applications based on deep neural networks. End-to-end learning allows to: 1) automatically learn features directly from simple wireless signal representations, without requiring design of hand-crafted expert features like higher order cyclic moments and 2) train wireless signal classifiers in one end-to-end step which eliminates the need for complex multi-stage machine learning processing pipelines. The purpose of this paper is to present the conceptual framework of end-to-end learning for spectrum monitoring and systematically introduce a generic methodology to easily design and implement wireless signal classifiers. Furthermore, we investigate the importance of the choice of wireless data representation to various spectrum monitoring tasks. In particular, two case studies are elaborated: 1) modulation recognition and 2) wireless technology interference detection. For each case study three convolutional neural networks are evaluated for the following wireless signal representations: temporal IQ data, the amplitude/phase representation, and the frequency domain representation. From our analysis, we prove that the wireless data representation impacts the accuracy depending on the specifics and similarities of the wireless signals that need to be differentiated, with different data representations resulting in accuracy variations of up to 29%. Experimental results show that using the amplitude/phase representation for recognizing modulation formats can lead to performance improvements up to 2% and 12% for medium to high SNR compared to IQ and frequency domain data, respectively. For the task of detecting interference, frequency domain representation outperformed amplitude/phase and IQ data representation up to 20%
A survey on machine learning-based performance improvement of wireless networks: PHY, MAC and network layer
No full textThis paper presents a systematic and comprehensive survey that reviews the latest research efforts focused on machine learning (ML) based performance improvement of wireless networks, while considering all layers of the protocol stack: PHY,MAC and network. First, the related work and paper contributions are discussed, followed by providing the necessary background on data-driven approaches and machine learning to help non-machine learning experts understand all discussed techniques. Then, a comprehensive review is presented on works employing ML-based approaches to optimize the wireless communication parameters settings to achieve improved network quality-ofservice (QoS) and quality-of-experience (QoE).We first categorize these works into: radio analysis, MAC analysis and network prediction approaches, followed by subcategories within each. Finally, open challenges and broader perspectives are discussed.Signal Processing System
Μετάφραση και μεταφραστικός σχολιασμός αποσπάσματος από το βιβλίο της Ayşe Kulin ''Füreya'' σελ. 229-257.
No full textΤο μυθιστότημα της Ayşe Kulin πραγματεύεται τη ζωή της Füreya. Μιας από τις πρώτες κεραμίστριες της Τουρκίας που προσβλήθηκε απο φυματίωση και που έζησε την ίδια περίοδο των μεγάλων αλλαγών της Τουρκίας από τον Κεμάλ Αττατούρκ,την περίοδο της Δημοκρατίας. Γυναίκα με ανήσυχο πνεύμα,κάνοντας δύσκολα συμβιβασμούς και παντρεμένη με τον στρατιωτικό Kılıç Ali υπέρμαχο στο πλευρό του Κεμάλ Αττατούρκ. Στο απόσπασμα που κλήθηκα να μεταφράσω έγινα μάρτυρας της αέναης προσπάθειάς της να θεραπευτεί ολοκληρωτικά από την ασθένειά της φτάνοντας στο σημείο να ζητήσει να υποβληθεί σε ακραίες ιατρικές μεθόδους. Μοναδικός της συμπαραστάτης και πυγμαλίων ο κύριος Σεβκί ο οποίος βρισκόταν πάντα στο πλευρό της θαυμάζοντάς την ώς καλλιτέχνιδα αλλά και ως γυναίκα. Γινόμαστε μάρτυρες όμορφων και γλαφυρών εικόνων όσων αφορά τα καλλιτεχνήματά της αλλά και εικόνων ανησυχίας και απελπισίας σε ότι αφορά την ασθένειά της. Γυρνώντας στην Κωνσταντινούπολη, μετά την παραμονή της στο σανατόριο του Λεϊσίν,επισκέπτεται την ανηψιά της η οποία μόλις έχει γεννηθεί και εκεί νιώθουμε την σύγχυση στην οποία έχει επέλθει η πρωταγωνίστρια καθώς κάποια χρόνια πριν έχασε την μονάκριβη κόρη της. Η συγγραφέας πλάθει εικόνες συναισθημάτων και πραγματικών γεγονότων ενώ έκδηλη είναι η μελαγχολία που αποπνέει στον αναγνώστη ενώ στο τέλος η ηρωίδα του μυθιστορήματος εκπνέει.Ayşe Kulin's novel deals with the life of Füreya. One of Turkey's first tuberculosis-infected tuberculosis, who lived during the same period of the great changes of Turkey by Kemal Atatürk during the period of the Republic. A woman with restless spirit, making difficult compromises and married to militant Kılıç Ali supporter at the side of Kemal Atatürk. In the excerpt I was asked to translate, I witnessed her infinite attempt to cure her illness completely, reaching the point of asking to undergo extreme medical methods. Singer of the supporter and pianist Mr. Sequi who was always on her side admiring her as an artist but also as a woman. We are witnesses of beautiful and brilliant images of her arts, as well as of images of anxiety and despair as to her illness. Turning to Constantinople after her stay at Leesin's sanatorium, she visits her nephew, who has just been born, and we feel the confusion that the protagonist has made, as she lost her one-time daughter some years before. The author creates images of emotions and real events, while the melancholy exuding the reader is evident, while the heroine of the novel exits
Wind effect on pre-existing waves
No full textWind action on pre-existing ,waves is examined experimentally in a wind-wave channel, in which the pre-existing waves are generated mechanically by a paddle at the windward end of the channel. Air is blown over these waves, in the direction of ,·rave travel, at velocities up to about 30 feet per second, with the formation of wind-generated waves essentially suppressed by addition of a wetting agent to the water. Wind shear forces on these regular wavy surfaces are deduced for a variety of wave geometries
Towards a cognitive MAC layer: Predicting the MAC-level performance in dynamic WSN using machine learning
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Towards a cognitive MAC layer: Predicting the MAC-level performance in dynamic WSN using machine learning
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