An Analytical Model for Virtual Topology Reconfiguration in Optical Networks and A Case Study

An analytical model for Virtual Topology Reconfiguration (VTR) in optical networks is developed. It aims at the optical networks with a circuit-based data plane and an IPlike control plane. By identifying and analyzing the important factors impacting the network performance due to VTR operations on both planes, we can compare the benefits and penalties of different VTR algorithms and policies. The best VTR scenario can be adaptively chosen from a set of such algorithms and policies according to the real-time network situations. For this purpose, a cost model integrating all these factors is created to provide a comparison criterion independent of any specific VTR algorithm and policy. A case study based on simulation experiments is conducted to illustrate the application of our models.

Performance Analysis of Sparse Traffic Grooming in WDM Mesh Networks

Sparse traffic grooming is a practical problem to be addressed in heterogeneous multi-vendor optical WDM networks where only some of the optical cross-connects (OXCs) have grooming capabilities. Such a network is called as a sparse grooming network. The sparse grooming problem under dynamic traffic in optical WDM mesh networks is a relatively unexplored problem. In this work, we propose the maximize-lightpath-sharing multi-hop (MLS-MH) grooming algorithm to support dynamic traffic grooming in sparse grooming networks. We also present an analytical model to evaluate the blocking performance of the MLS-MH algorithm. Simulation results show that MLSMH outperforms an existing grooming algorithm, the shortest path single-hop (SPSH) algorithm. The numerical results from analysis show that it matches closely with the simulation. The effect of the number of grooming nodes in the network on the blocking performance is also analyzed.

Impact of Bottom Flange Confinement Reinforcement on Performance of Prestressed Concrete Bridge Girders

For many years AASHTO provided no recommendation to state DOT’s on bottom flange confinement reinforcement for their bridge superstructures. The 1996 edition of AASHTO Standard Specification for Highway Bridges stated that nominal reinforcement be placed to enclose the prestressing steel from the end of the girder for at least a distance equal to the girder’s height. A few years later the 2004 AASHTO LRFD Bridge Design Specification changed the distance over which the confinement was to be distributed from 1.0h to 1.5h, and gave minimum requirements for the amount of steel to be used, No.3 bars, and their maximum spacing, not to exceed 6”. Research was undertaken to study what impact, if any, confinement reinforcement has on the performance of prestressed concrete bridge girders. Of particular interest was the effect confinement had on the transfer length, development length, and vertical shear capacity of the fore mentioned members. First, an analytical investigation was performed on the subject, and then an experimental investigation followed which consisted of designing, fabricating, and testing eight tee-girders and three NU1100 girders with particular attention paid to the amount and distribution of confinement reinforcement placed at the end of each girder. The results of the study show: 1) neither the amount or distribution of confinement reinforcement had a significant effect on the initial or final transfer length of the prestress strands; 2) at the AASHTO calculated development length, no significant impact from confinement was found on either the nominal flexural capacity of bridge girders or bond capacity of the prestressing steel; 3) the effects from varied confinement reinforcement on the shear resistance of girders tested was negligible, however, distribution of confinement did show to have an impact on the prestressed strands’ bond capacity; 4) confinement distribution across the entire girder did increase ductility and reduced cracking under extreme loading conditions.

THE FLUTE MUSIC OF PAUL DESENNE: A COMPARATIVE ANALYTICAL STUDY OF REPRESENTATIVE WORKS

The significance of the works by Venezuelan-born composer Paul Desenne lies in his unique compositional style that incorporates elements of Latin American folk, pop, and traditional music within the framework of the Western European tradition. His works, though easily classified as art music, nevertheless gain much of their emotional and referential meaning through this rich borrowing. This document focuses on three of Desenne’s flute pieces: the Solo Flute Sonata (2001), Gurrufío for flute orchestra (1997), and Guasa Macabra for flute and clarinet (2003). It provides an analysis of the three works, examining formal, structural, motivic, and rhythmic aspects. Scores and interviews with the composer have been employed as primary sources. Bibliographical material closely related to his music and other secondary sources support this analytical approach. This document also provides an introduction and stylistic discussion of Desenne’s other pieces that incorporate the flute. Chapter one consists of an introduction to Desenne’s life and general considerations of his musical style. Each of the following three chapters focuses on one the three aforementioned flute works, including information about the composition and premiere of each piece as well as analysis and an examination of its incorporation of traditional folk elements. The final chapter presents an introduction to and stylistic discussion of the other flute pieces by this composer. This study intends to provide a basic understanding of Desenne’s flute music, including general characteristics of his musical style, paving the way for further investigation of Desenne’s music, and flute music in particular.