The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

Thesis advisor: Renato Mirollo / There are countless occurrences of oscillating systems in nature. Climate cycles and planetary orbits are a few that humans experience daily. Man has also incorporated, to his benefit, oscillation into his craft; the grandfather clock, for example, can keep track of time with astounding accuracy using the period of a long pendulum. Such systems can range in complexity in a number of ways. The governing equation for a given oscillator could be as simple as a sine curve, or its motion could appear so erratic that oscillatory motion is undetectable to viewers. The number of oscillators in a system can also vary, and oscillators can be coupled; that is, oscillators can be affected by the motion of neighboring oscillators. It is this last case we wish to study. We will briefly look at the case of finitely many oscillators and then move to analyzing a model consisting of infinitely many identical oscillators. Synchrony is the simplest collective behavior. We will study a more complicated pattern called splay states in which oscillators are equally staggered in phase, i.e. phase locked such that the system will return to this pattern if it is disturbed by an arbitrarily small amount. Mathematically, this requires us to find attracting fixed points in the system. We will approximate the local behavior of our model by linearizing the system near its fixed points. We will then apply our findings to a few specific cases of such models including: uniform density, linear distribution, alpha-function pulses, and integrate-and-fire. / Thesis (BS) — Boston College, 2013. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Mathematics.

Θέμα της παρούσης διπλωματικής εργασίας αποτελεί η μελέτη, ανάπτυξη και πειραματική επιβεβαίωση αλγοριθμικών τεχνικών για την σχεδίαση αυτοοργανώμενων δομών δεδομένων (self-organizing data structures) και η ανάπτυξη τυχαιοποιημένων εκδόσεών τους. Μια αυτοοργανώμενη δομή δεδομένων διαθέτει κάποιον αλγόριθμο για να αναδιοργανώνει τους δείκτες και τα δεδομένα κατάστασης μετά από κάθε πρόσβαση ή πράξη . Ο αλγόριθμος αυτοοργάνωσης είναι σχεδιασμένος ώστε αντιδρώντας σε αρχικά άγνωστες ιδιότητες της ακολουθίας αιτήσεων (request sequence), να οδηγεί τη δομή δεδομένων σε κατάσταση πλεονεκτική για τις ιδιότητες της ακολουθίας με αποτέλεσμα τη μείωση του χρόνου που χρειάζεται στο μέλλον ανά πράξη. Ο πρώτος αλλά και ο μόνος μέχρι σήμερα πιθανός υποψήφιος αλγόριθμος αναζήτησης σε δένδρο που μπορεί να είναι Ο(1)-ανταγωνιστικός είναι το splay δένδρο (splay tree) που παρουσιάστηκε από τους Sleator και Tarjan [1]. Στην εργασία των Sleator και Tarjan παρουσιάζονται κάποιες εικασίες, οι οποίες δεν έχουν αποδειχθεί. Σημαντικότερη είναι η εικασία δυναμικής βελτιστότητας (dynamic optimality conjecture) σύμφωνα με την οποία το splay δένδρο είναι Ο(1)-ανταγωνιστικό. Η εικασία δυναμικής δακτυλοδότησης (dynamic finger conjecture) και η εικασία διαπέρασης (traversal conjecture) είναι αληθείς, αν είναι αληθής η εικασία δυναμικής βελτιστότητας. Ο Cole [3], [4] προσπάθησε να αποδείξει την ορθότητα της εικασίας δυναμικής δακτυλοδότησης σε μια από τις σημαντικότερες εργασίες για τα splay δένδρα. O J. Iacono [2] ανέπτυξε εναλλακτικές δομές δεδομένων που έχουν χρόνο χειρότερης περίπτωσης ανά πράξη (και όχι επιμερισμένο κόστος) της τάξης του Ο(logn), σε αντιδιαστολή με τον Ο(n) χρόνο χειρότερης περίπτωσης των splay trees. Σε αντιπαράθεση με τη δομή του Iacono, οι Mihai Badoiu και Erik D. Demaine παρουσίασαν μια δυναμική δομή αναζήτησης[7], η οποία επιτυγχάνει την ενοποιημένη ιδιότητα και που είναι απλούστερη από τη δομή του Iacono. Μεταξύ όλων των δυναμικών δομών αναζήτησης με βάση τις συγκρίσεις , η συγκεκριμένη δομή έχει τον καλύτερο χρόνο εκτέλεσης. Εκτός της παραπάνω δομής, ο Demaine ανέπτυξε ένα Ο(loglogn) ανταγωνιστικό online δυαδικό δέντρο αναζήτησης[5] , βελτιώνοντας το μέχρι πρότινος βέλτιστο ανταγωνιστικό ποσοστό της τάξης Ο(logn). Αυτή είναι η πρώτη μεγάλη βελτίωση της εικασίας δυναμικής βελτιστότητας (dynamic optimality conjecture) των Sleator και Tarjan , σύμφωνα με την οποία υπάρχουν Ο(1) ανταγωνιστικά δυαδικά δέντρα αναζήτησης. Σε σχέση με τη δυναμική βελτιστότητα των Splay trees, σημαντική συνεισφορά αποτελεί και η εργασία του George F. Georgakopoulos[6]. Ο George F. Georgakopoulos παρουσιάζει μια επέκταση της splay τεχνικής , την οποία ονομάζει chain-splay(αλυσιδωτό splay) . Τα chain-splay δέντρα εφαρμόζουν splay στο στοιχείο που προσπελαύνουμε προς τη ρίζα όπως ακριβώς γίνεται και στα κλασικά splay trees, αλλά εκτελούν και μερικές τοπικές splay πράξεις τακτοποίησης κάτω από το στοιχείο που προσπελάσαμε. Αποδεικνύεται πως η τεχνική chain–splay είναι Ο(loglogn) ανταγωνιστική σε σχέση με οποιοδήποτε offline αλγόριθμο αναζήτησης. Tέλος, ο George F. Georgakopoulos [9] έδωσε ένα νέο λήμμα επαναζύγισης για τα splay δέντρα και με βάση αυτό το λήμμα, αποδεικνύει πως τα splay δέντρα είναι ανταγωνιστικά προς κάθε κλάση δυναμικών ισοζυγισμένων δέντρων. Οι παραπάνω δομές θα μελετηθούν τόσο σε θεωρητικό όσο και σε πειραματικό επίπεδο με σκοπό την εξαγωγή χρήσιμων συμπερασμάτων σε σχέση με την αποδοτικότητά τους αλλά και με σκοπό την καταγραφή των ακόμη ανοικτών προβλημάτων και των προοπτικών επίλυσης τους. Επιπλέον, θα παρουσιαστούν τυχαιοποιημένες εκδόσεις των δομών των Demaine και Georgakopoulos. Οι δομές αυτές θα υλοποιηθούν και η απόδοσή τους θα τεκμηριωθεί τόσο πειραματικά όσο και θεωρητικά. Σημαντικής σημασίας είναι η σύγκρισή τους με τις αρχικές δομές, ώστε να εξαχθούν συμπεράσματα σχετικά με την συμβολή της τυχαιοποίησης στη βελτίωση της απόδοσης των δομών. / -

Magister Curationis / Binary search trees (BSTs) are important data structures which are widely used in various guises. Splay trees are a specific kind of binary search tree, one without explicit balancing. Skip lists use more space than BSTs and are related to them in terms of much of their run-time behavior. Even though binary search trees have been used for about half a century, there are still many open questions regarding their run-time performance and algorith mic complexity. In many instances, their worst-case, average-case, and best-case behaviors are unknown and need further research. Our analysis provides a basis for selecting more suitable data structures and algorithms for specific processes and applications. We contrast the empirical behavior of splay trees and skip lists with their theoretical behavior. In particular we explore when splay trees outperform skip lists and vice versa. The performance of a splay tree depends on the history of accesses to its el ements. On the other hand, the performance of a skip list depends on an indepen dent randomization of the height of links that lead to specific elements. Therefore, probabilistic methods are used to analyze the operation of splay trees and skip lists. Our main results are that splay trees are faster for sorted insertion, where AVL trees are faster for random insertion. For searching, skip lists are faster than single class top-down splay trees, but two-class and multi-class top-down splay trees can behave better than skip lists.

In this thesis we compared some variants of binary search trees that approach dynamic optimality: Tango trees, Multisplay trees, and Splay trees. We empirically tested the behavior of these three types of trees, as well as Red-Black trees. We measured the amount of visited nodes per operation and running time on real hardware. We proved that Tango trees and Multisplay trees are in most cases less efficient than Splay trees and Red-Black trees. Cache-related effects played a surprisingly large part in the behavior of Red-Black tree and Splay tree. 1

<p>Our main results are that splay trees are faster for sorted insertion, where AVL trees are faster for random insertion. For searching, skip lists are faster than single class top-down splay trees, but two-class and multi-class top-down splay trees can behave better than skip lists.</p>

The use of fiber reinforced polymers (FRP's) for structural repair or retrofit has increased significantly in the last decade, with adoption for civil infrastructure occurring only in the last 20 years. These products are most often used to increase the capacity of damaged or deteriorated structures. Much research has been performed in the arena of testing of various FRP's bonded to both concrete and masonry substrates, the majority of which focusing on three areas; flexural strengthening, in-plane shear strengthening, and mechanical anchoring. Anchorage is commonly the limiting factor in the application of FRP's, due to the inability of the edge of the polymer matrix to reliably extend beyond a point of zero-interfacial stress. Where interfacial stresses exist and the FRP is terminated localized disbondment often occurs, these localized failures then propagate across the entire bond of the structural system. Various mechanical termination details have been tested to mitigate the potential failure modes near the ends of the fabric. There, however, has been very limited research performed on the behavior of dowels which are installed parallel to the FRP fabric and splayed onto the FRP fabric matrix. In this research the mechanical properties of carbon fiber reinforced polymer (CFRP) dowels with a parallel orientation to uniaxial carbon fabric are experimentally tested to determine the tensile capacity of "dowel to splay" CFRP connections and to discover any dominant failure modes.