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Optical peripheral circuits for high-speed WDM-enabled optical RAMs
No full textRecently, significant research demonstrations in photonic technology have been reported such as the optical memory implementations. In the near future, optical memories will probably replace their electronic counterparts, since they can offer many advantages in terms of speed, footprint and power consumption. Although the positive impact of photonic technology in HPC infrastructure is already obvious with both optical memories and optical interconnect implementations, there are still some missing fundamental parts between CPU-Memory that need to be implemented with optics. These peripheral components such as optical row/column decoders are responsible for decoding and routing the optical data to a specific memory location. Their implementation will consist the optical interface that will allow for complete functional 2D optical memory realization. The main objective of this PhD thesis is the design, development and evaluation of all-optical architectures that will be employed in optical memory interface implementation such as optical access gates and row/column decoders. The proposed optical circuits rely on SOA-based implementations to achieve high throughput, low fabrication complexity and low power consumption by exploiting the wavelength division multiplexing (WDM) technique. In this PhD thesis, design and detailed studies of a multiwavelength SOA-based optical access gate were performed at 10Gb/s. This optical switch supports the WDM technique and as a result the power consumption of the optical RAM architecture can be minimized through efficient hardware sharing. In addition, a novel architecture for an all-optical passive 2×4 row decoder is also proposed in this PhD thesis. The all-optical passive 2×4 row decoder is combined with a multiwavelength optical access gate and a passive column decoder to provide full access to a 4×2 optical RAM bank. The proposed architecture was experimentally confirmed at 10Gb/s for two alternative access gates. The second section of the PhD discusses optical memory circuits that exploit a passive optical feedback loop in order to perform bit storing in the optical domain. More specifically, an all-optical Τ flip-flop is demonstrated, relying its operation on an SOA-MZI interferometer and a feedback loop. The same all-optical Τ flip-flop circuit is, then, used in cascade to serve as 2-bit all-optical counter. These circuits can have a critical impact in case of complex optical peripheral implementations such as shift registers and PRBS generators. In that case, many cascaded stages of these circuits should be employed, yielding to multiple SOAs placed in a row. However, the accurate design of an optical system would require a prior study on the optical degradation induced by SOA elements, during the amplification process. On that account, a theoretical study was performed, in the frame of the present PhD thesis, in order to investigate the Deterministic Timing Jitter and Peak power equalization induced by the SOA.Η ανάπτυξη της φωτονικής τεχνολογίας οδήγησε στην υλοποίηση οπτικών μνημών τυχαίας προσπέλασης που μπορούν να χρησιμοποιηθούν σε αντικατάσταση των ηλεκτρονικών αναλόγων τους, προσφέροντας σημαντικά πλεονεκτήματα αναφορικά με την ταχύτητα, το ίχνος επιφάνειας και την κατανάλωση ενέργειας. Αν και με την βοήθεια της φωτονικής τεχνολογίας φαίνεται σταδιακά να αναπτύσσεται η νέα πρωτοποριακή υποδομή των υπερυπολογιστών τόσο σε επίπεδο οπτικών διασυνδέσεων όσο και σε επίπεδο οπτικών μνημών, κάποια βασικά περιφερειακά συστήματα που θα καταστήσουν πλήρως λειτουργική την σύνδεση του επεξεργαστή - οπτικής μνήμης ακόμη απουσιάζουν. Τα περιφερειακά συστήματα μιας οπτικής μνήμης είναι τα βασικά εκείνα στοιχεία που αποτελούν την διεπαφή της μνήμης και είναι υπεύθυνα για ένα πλήθος λειτουργιών όπως αποκωδικοποίηση διευθύνσεων γραμμής/στήλης και έλεγχο πρόσβασης των οπτικών δεδομένων στο οπτικό κελί αποθήκευσης. Το βασικό αντικείμενο της παρούσας διδακτορικής διατριβής είναι ο σχεδιασμός και η μελέτη αμιγώς οπτικών κυκλωμάτων για την ανάπτυξη οπτικής διεπαφής . Τα προτεινόμενα οπτικά κυκλώματα εκμεταλλεύονται τους τεχνολογικά ώριμους οπτικούς ενισχυτές SOA για την επίτευξη υψηλής ρυθμοαπόδοση, χαμηλής κατασκευαστικής πολυπλοκότητα αλλά και χαμηλής κατανάλωσης ενέργειας μέσω της τεχνικής πολυπλεξίας με διαίρεση μήκους κύματος. Στο πλαίσιο της παρούσας διδακτορικής διατριβής, πραγματοποιήθηκε σχεδιασμός και μελέτη μιας οπτικής πολυκυματικής πύλης ελέγχου πρόσβασης στα 10Gb/s, η οποία βασίζεται σε ένα οπτικό ενισχυτή SOA. Επίσης, μελετήθηκε η αρχιτεκτονική ενός οπτικού παθητικού 2×4 αποκωδικοποιητή διευθύνσεων γραμμής σε συνδυασμό με μια οπτική πολυκυματική πύλη ελέγχου πρόσβασης και έναν παθητικό αποκωδικοποιητή διευθύνσεων στήλης. Η οπτική αρχιτεκτονική επιβεβαιώθηκε πειραματικά στα 10Gb/s για δύο διαφορετικές οπτικές πύλες ελέγχου πρόσβασης. Ακόμη, εξετάστηκε το μέγιστο επιτρεπτό μέγεθος των οπτικών αποκωδικοποιητών που παρουσιάζονται μαζί με μια εναλλακτική αρχιτεκτονική για τον οπτικό παθητικό αποκωδικοποιητή διευθύνσεων που επιτρέπει πρόσβαση σε περισσότερες γραμμές της μνήμης με την ίδια κατανάλωση ενέργειας. Επιπλέον, μελετώνται οπτικά κυκλώματα μνήμης που εκμεταλλεύονται έναν παθητικό βρόχο ανάδρασης για να επιτύχουν αποθήκευση στο οπτικό πεδίο. Συγκεκριμένα, παρουσιάζεται ένα οπτικό κύκλωμα Τ flip-flop που αποτελείται από ένα οπτικό συμβολόμετρο SOA-ΜΖΙ μαζί με ένα παθητικό βρόχο ανάδρασης. Στην συνέχεια, εξετάζεται το ίδιο κύκλωμα σε διασύνδεση για την επίτευξη της λειτουργίας ενός 2-bit οπτικού μετρητή. Αυτά τα κυκλώματα μνήμης αποτελούν ιδανικούς υποψηφίους για οπτικές υλοποιήσεις πιο περίπλοκων περιφερειακών συστημάτων, όπως είναι οι καταχωρητές ολίσθησης και οι γεννήτριες ψευδοτυχαίας ακολουθίας bit. Σε μια τέτοια περίπτωση, απαιτείται η διασύνδεση πολλαπλών σταδίων οπτικών ενισχύτων SOΑ και κατ’ επέκταση ο ορθός σχεδιασμός του οπτικού συστήματος προϋποθέτει την μελέτη της υποβάθμισης που εισάγει ο κάθε ενισχυτής SOA στα οπτικά σήματα σε κάθε στάδιο. Για το λόγο αυτό, πραγματοποιήθηκε στα πλαίσια της παρούσας διδακτορικής διατριβής θεωρητική μελέτη για την υποβάθμιση που εισάγει ο SOA στα οπτικά σήματα κατά την διαδικασία ενίσχυσης. Συγκεκριμένα, μελετήθηκε η ντετερμινιστική χρονική ολίσθηση αλλά και οι ιδιότητες της εξίσωσης ισχύος που προκαλεί ο ενισχυτής σε εισερχόμενους ανισοϋψείς οπτικούς παλμούς
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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