External Memory Pipelining Made Easy With TPIE

When handling large datasets that exceed the capacity of the main memory, movement of data between main memory and external memory (disk), rather than actual (CPU) computation time, is often the bottleneck in the computation. Since data is moved between disk and main memory in large contiguous blocks, this has led to the development of a large number of I/O-efficient algorithms that minimize the number of such block movements. TPIE is one of two major libraries that have been developed to support I/O-efficient algorithm implementations. TPIE provides an interface where list stream processing and sorting can be implemented in a simple and modular way without having to worry about memory management or block movement. However, if care is not taken, such streaming-based implementations can lead to practically inefficient algorithms since lists of data items are typically written to (and read from) disk between components. In this paper we present a major extension of the TPIE library that includes a pipelining framework that allows for practically efficient streaming-based implementations while minimizing I/O-overhead between streaming components. The framework pipelines streaming components to avoid I/Os between components, that is, it processes several components simultaneously while passing output from one component directly to the input of the next component in main memory. TPIE automatically determines which components to pipeline and performs the required main memory management, and the extension also includes support for parallelization of internal memory computation and progress tracking across an entire application. The extended library has already been used to evaluate I/O-efficient algorithms in the research literature and is heavily used in I/O-efficient commercial terrain processing applications by the Danish startup SCALGO

Quantum Limits of Eisenstein Series and Scattering states

We identify the quantum limits of scattering states for the modular surface. This is obtained through the study of quantum measures of non-holomorphic Eisenstein series away from the critical line. We provide a range of stability for the quantum unique ergodicity theorem of Luo and Sarnak.Comment: 12 pages, Corrects a typo and its ramification from previous versio

“The Great Speckled Bird”- Early Country Music and the Popularization of Non-Secular Song

Perhaps no melody in the country music canon has been as widely recognized and borrowed from as that of the song “The Great Speckled Bird.” This significant song has become resonant and representative of both country music culture and religious culture of the Protestant South. Through this historiographical study, I have traced the influences that helped shape “The Great Speckled Bird” and in so doing have illustrated distinct movements that led to popularizing the non-secular song through commercial country music. The composer’s use of sentimentality, neo- traditionalism, and religious ideas made it appealing to a rural southern culture struggling with the social, racial, and economic changes of the early twentieth century. As I develop and explore the diverse influences that helped to shape “The Great Speckled Bird,” I will illustrate the interconnectedness of country music culture and the wider popular and religious cultures of the white Protestant South