Improving efficiency for GPUs with decoupled delegate

GPUs are increasingly used for general-purpose computation. For many applications, GPUs achieve significant performance advantages over CPUs, largely due to GPUs’ ability to exploit massive parallelism. However, massive parallelism can cause inefficiency for many operations, such as concurrent data structures. Symptoms include synchronization bottleneck and redundant overheads. To make such operations efficient, our key strategy is to decouple them from the rest of GPU program. Then, we use a few threads acting as a delegate to perform the decoupled operations on behalf of all other threads. This reduces the synchronization for decoupled operations because fewer threads are used. In addition, the delegate amortizes overheads for other threads, similar to the way in which vector execution amortizes instruction overheads. The cost of our approach is the need for communication between the delegate and other threads. We develop innovative ways to reduce the communication so that the benefit strongly outweighs the cost. Based on the strategy, we propose three solutions for both regular and irregular workloads. For regular GPU workloads, our solution reduces repetitive ALU OPs and instruction execution, while reducing memory latency with non-speculative prefetching. This approach enabled our solution to achieve 40.7% speedup and 20.2% energy reduction on average for 29 benchmarks. For lock-based workloads, our solution avoids destructive lock contention in global memory and thus achieves an average speedup of 3.6x, implemented entirely in software. Finally, we introduce a new GPU single source shortest path (SSSP) algorithm with a complex worklist; it offers many benefits compared to a simpler worklist but incurs significant overheads. However, our decoupled delegate approach reduces the overheads and makes the complex worklist design efficient for GPUs. Hence, our solution, implemented in software, achieved an average speedup of 2.8x over 226 graphs compared with state-of-the-art approaches.Computational Science, Engineering, and Mathematic

Applications of desorption electrospray ionization mass spectrometry imaging for disease characterization from tissue sections and minimally invasive biopsies

Due to improved therapeutic regimens for cancer, disease grade, stage, and subtype, have become pertinent stratifications for prescribing an optimized treatment plan for every patient. Histopathologists are now being asked to perform increasingly complex disease distinctions from small biopsy samples that may or may not provide the necessary information to make such distinctions. Since inception, mass spectrometry (MS) have been proven to be a powerful analytical tool for disease diagnosis and several MS techniques have been successfully integrated into routine clinical workflows. Over the past two decades, ambient ionization MS, particularly desorption electrospray ionization mass spectrometry imaging (DESI-MSI), has been studied for disease differentiation in a similar manner. Intrinsic advantages of DESI-MSI, such as minimal sample preparation, nondestructive solvent system, and spatial separation of relevant tissue, supports the successful integration of this technology into a pathological workflow. Despite these advantages, research is ongoing to determine the efficacy of DESI-MSI as a tool for intricate disease stratification and biopsy analysis. This dissertation presents the applications of DESI-MSI towards staging advanced disease, classifying preneoplastic lesions, and subtyping cancerous tissue from tissue sections and minimally invasive biopsy material. Chapter 2 discusses the application of DESI-MSI and statistical analyses to understand metabolic dysregulation in primary and metastatic melanoma as well as discusses the performance of statistical classifiers on metastatic melanoma in lymph node tissue. Chapter 3 presents the application of DESI-MSI and statistical classifiers towards differentiation of low grade and high grade preneoplastic pancreatic cysts. Finally, Chapter 4 describes the application of this technique towards the stratification of lung cancer subtypes from tissue sections and biopsy material. In entirety, this work aims to demonstrate the capabilities of the DESI-MSI workflow towards increasingly complex biospecimens and diagnostic challenges commonly confronted in routine clinical environments.Chemistr

The justification of religious intolerance : an examination of the American media's responses to the life and crimes of Nidal Hasan

An examination of the crimes of Nidal Hasan through the lens of American News media. This document examines the production of religious extremism in relation to Islam for the consumption of the American public and how it is reductive and harmful to Muslims.Religious Studie

Investigation of vertical shear strength in unreinforced interfaces between concrete cast at different times

This thesis presents an experimental study of vertical interface shear strength between layers of concrete cast at different times. Current design provisions allow only for load to be transferred across reinforced interfaces. However, previous research has suggested that unreinforced interfaces can be manipulated to sustain significant load transfer. The first part of this project was to identify key factors affecting interface shear strength through a review of previous research. The key factors identified were interface roughness, differential stiffness, and differential shrinkage. To quantify the effects of these factors, an experimental program consisting of twenty-seven specimens was conducted in two phases. Phase one consisted on specimens with a precast shell and a cast-in-place core, while phase two consisted of a cast-in-place shell with a precast core. The variables tested were smooth interfaces compared to rough, sandblasted interfaces, conventional concrete compared to shrinkage reducing concrete, and circular compared to square interfaces. Interface slip data was also recorded to better characterize the behavior of the interfaces under loading. Interface strengths observed ranged from 41 psi to 236 psi. It was found that roughened, circular interfaces tended to be the strongest and circular smooth interfaces with shrinkage reducing concrete were the weakest. Results indicated that circular interfaces were preferable compared to square interfaces. Further, the use of shrinkage reducing admixture greatly reduced interface shear strength, which was an unexpected result. Finally, it was concluded that interface roughening, even in a modest amount, can provide significant strength gains independent of concrete strength or stiffness. This research also suggests a modified version of the AASHTO interface shear transfer equation to allow for future discussion on the use of unreinforced interfaces in design applications.Civil, Architectural, and Environmental Engineerin

Internationalization at striving universities and the role of presidential leadership

Over the past two decades, there has been heightened awareness and intensified discussions on the importance of internationalization in the academy. There are also strong calls for action from university leaders, faculty members, and industry CEOs. Equipping students with the skills, knowledge, and attitudes necessary to live and thrive in today’s globally interconnected and interdependent world has never been an ambiguity. However, there seems to be little discussion and research on the limited role of presidential leadership in comprehensive internationalization efforts at U.S. universities (Hudzik, 2015). Motivated by the ACE model for comprehensive internationalization, this study explores actionable frameworks to support campus internationalization goals. This qualitative research project utilizes a multiple case study approach to better understand the role that presidential leadership plays in comprehensive internationalization at striving universities. I argue that the rise or fall of the internationalization agenda largely depends on Presidential leadership. Presidents must lead the charge for the work of internationalization to be effective and successful at higher education institutions.Educational Leadership and Polic

Best Practices for Queer Metadata

This document is the result of two years of work by a group of nearly one hundred knowledge organisers, cataloguers, librarians, archivists, scholars, and information professionals with a concerted interest in improving the metadata treatment of queer people, communities, and items in GLAMS (Galleries, Libraries, Archives, Museums, and Special Collections) and other informational institutions. Their work has been supported by over 800 peer reviewers; combined, these groups make up the Queer Metadata Collective (QMDC). The QMDC builds upon earlier work done by the Trans Metadata Collective (TMDC), a similarly-organised group of metadata workers and information professionals with a concerted interest in improving the metadata representation of trans and gender-diverse people. The work of the TMDC culminated in Metadata Best Practices for Trans and Gender Diverse Resources, focusing on the description, cataloguing, and classification of information resources as well as the creation of metadata about trans and gender-diverse people, including authors, communities, and other creators. Following the publication of the Best Practices, several TMDC members founded and developed the QMDC over the summer of 2022. This document focuses on metadata by and about queer people, communities, and resources. While there is significant overlap between queer metadata and trans and gender diverse metadata, QMDC’s recommendations should not be seen as excluding or superseding TMDC’s, as trans and gender diverse people, communities, and resources have specific needs. For best practices and recommendations about trans and gender-diverse resources, please consult the TMDC document. If the TMDC and QMDC recommendations conflict (we are not aware of any instances in which they do), prefer the TMDC document for trans and gender diverse resources and the QMDC for other types of queer resources.UT Librarie

Randomized algorithms for the efficient solution of elliptic PDEs on modern architectures

This thesis describes techniques for efficiently and robustly computing approximate solutions to elliptic partial differential equations (PDEs). It presents novel algorithms for solving linear systems that exploit randomized methods in linear algebra to attain high computational efficiency and scalability. These algorithms are designed to leverage a variety of compute kernels, such as vectorization and specialized hardware acceleration features found on modern architectures. The ideas in this thesis demonstrate viable paths to re-envisioning classical linear solvers in a changing hardware landscape. The unifying theme of the work is the use of hierarchical matrices (-matrices) to accelerate key compute kernels. The term -matrix refers to a matrix that can hierarchically be tessellated into submatrices in such a way that each submatrix is either of low numerical rank, or small enough that it can be stored densely. Using -matrix representation for a matrix of size × allows the complexity of matrixvector products and matrix inversion to have linear, or close to linear, complexity when dense linear algebra would require (²) and (³) operations, respectively. In this thesis, -matrix structure is used to represent discretized integral equations, as well as to represent large dense matrices that arise in sparse direct solvers for discretized PDEs. The thesis contains three key contributions. First, a novel fast multipole method (FMM) is presented. This is a fast algorithm for applying an -matrix to a vector, with applications in the numerical solution of integral equation formulations of PDEs using iterative methods. The method is based on linear algebraic tools such as randomized low rank approximation, and “skeleton representations” of far-field interactions. Its key feature is significantly simplified data structure compared to the original FMM. Second, a sparse direct solver for discretized PDEs is presented, which is compatible with a variety of PDE discretizations. This work addresses a critical limitation of sparse direct solvers, which is that techniques such as LU and Cholesky lead to factors that are far less sparse than the original matrix; we ameliorate this “fill-in” effect by exploiting -matrix structure in the dense blocks that arise. This solver distinguishes itself from related work by using a decomposition of the computational domain into slabs. This approach leads to simplified data structures, which facilitate parallelization and also makes the scheme more amenable to using GPU acceleration for improved performance. Third, a novel algorithm for the simultaneous compression and LU factorization of a particular class of -matrices is presented. This process is achieved in linear time from black-box matrix-vector products of an operator with -matrix structure. The work builds upon a previously proposed algorithm for “strong recursive skeletonization” but provides significant simplifications and accelerations. The work has applications in the direct solution of boundary integral equations and in sparse direct solvers for discretized PDEs.Computational Science, Engineering, and Mathematic

Breaking the ice : vulnerable disclosure in newly formed romantic relationships

People in newly formed romantic relationships often grapple with the choice to disclose or not disclose vulnerable information to their romantic partner. The current longitudinal study used Communication Privacy Management Theory (CPM) and appraisal theories of emotion to explore speakers’ experience of vulnerable disclosure from anticipation through enactment. To better understand the meaning of ‘vulnerability’ in interpersonal interaction, this study offered a conceptual definition of vulnerability, tested a four factor construct of vulnerability, and assessed the extent to which speakers felt eleven affective states prior to and following a vulnerable disclosure. Post interaction affective states and partner response discrepancies were evaluated to further probe the individual and relational outcomes of vulnerable disclosure. Lastly, connections were examined between speakers’ perceived risk and benefit of disclosing, perceived risk and benefit of not disclosing, and decision to disclose/not disclose. Findings suggested that speakers felt more negative affect than positive affect prior to disclosure. More specifically, speakers felt fear more than the remaining eight discrete affective states. Speakers who felt negative after disclosure were more likely to distance themselves from their relationship, whereas speakers who felt positive were not. Furthermore, relational distancing was less likely to occur when partners responded with more reciprocity or responsiveness than speakers anticipated. Moreover, speakers who received more responsiveness than they anticipated were more likely to report less negative affect following a vulnerable interaction. Results also demonstrated links between speakers’ perceived risk of disclosing and benefit of not disclosing as well speakers’ perceived benefit of disclosing and risk of not disclosing. Contrary to previous research, perceived risk of disclosing did not predict speakers’ decision to disclose/not disclose vulnerable information. Those who indicated greater risk than reward for not disclosing were more likely to disclose. Further inspection on risk demonstrated that speakers thought engaging in vulnerable disclosure would put their partner at risk more than themselves or their relationship. Despite differences in magnitude, risk type (i.e., self, partner, relationship) did influence speakers’ decisions to disclose/not disclose. Findings are discussed in accordance with study limitations and contributions to existing research.Communication Studie

Which policies are effective in increasing the number of children people have in low-fertility countries?

Many countries in Europe, North America, Oceania and parts of Asia have experienced significant declines in fertility. Long-term low fertility can put a strain on a country’s workforce, pension systems, and old age care, among others. Policymakers in many of these countries have implemented policies to make it easier for people to have and care for children. This brief, from PRC external faculty affiliate Wookun Kim and colleagues, reports on a recent review of dozens of experimental and quasi-experimental studies to evaluate whether policies affecting parental leave, childcare, direct financial incentives, and health insurance caused fertility to increase in low fertility countries. They show that policies that reduced the costs of childbearing were effective in increasing fertility, including policies that introduced, or generously prolonged, maternity leave; expanded public childcare; and implemented or expanded direct financial incentives. The authors argue that, to reduce workplace inequalities for women and inequalities in access to high quality childcare while also addressing policymakers’ goals of increasing fertility, policymakers should prioritize policies to promote lower-cost and higher-quality childcare for all of their inhabitants.Population Research Cente

Dynamics and regulation of polarity proteins during epithelial polarization in primed mouse embryonic stem cells

Epithelial polarity, defined by distinct apical and basolateral domains, is fundamental for animal embryonic development and organ function. During organogenesis, epithelia often develop from unpolarized precursor cells. How mammalian epithelial cells establish polarity de novo from an initially unpolarized state has remained unclear, in part due to an inability to observe this process in real time in non-transformed cellular systems. Here, we leverage recent advances in 3D spheroid culture of mouse embryonic stem cells, fluorescent protein knock-in and live imaging techniques to study the process of epithelial polarity establishment. We show that non-muscle myosin II (myosin) activity, regulated by MLCK, is crucial for the establishment and maintenance of epithelial polarity. Actomyosin cortical flows transport ZO-1, a tight junction component that interacts with apical polarity protein, to establish the apical membrane. A second pool of myosin, regulated by Rho kinase, localizes basally, and contributes to tissue shape. This implies the existence of opposing apical and basal actomyosin pools that regulate epithelial polarization. Our work paves the way for further exploration into the cellular basis of epithelial polarity establishment.Cellular and Molecular Biolog