Effective Performance Analysis and Debugging

Performance is once again a first-class concern. Developers can no longer wait for the next generation of processors to automatically optimize their software. Unfortunately, existing techniques for performance analysis and debugging cannot cope with complex modern hardware, concurrent software, or latency-sensitive software services. While processor speeds have remained constant, increasing transistor counts have allowed architects to increase processor complexity. This complexity often improves performance, but the benefits can be brittle; small changes to a program’s code, inputs, or execution environment can dramatically change performance, resulting in unpredictable performance in deployed software and complicating performance evaluation and debugging. Developers seeking to improve performance must resort to manual performance tuning for large performance gains. Software profilers are meant to guide developers to important code, but conventional profilers do not produce actionable information for concurrent applications. These profilers report where a program spends its time, not where optimizations will yield performance improvements. Furthermore, latency is a critical measure of performance for software services and interactive applications, but conventional profilers measure only throughput. Many performance issues appear only when a system is under high load, but generating this load in development is often impossible. Developers need to identify and mitigate scalability issues before deploying software, but existing tools offer developers little or no assistance. In this dissertation, I introduce an empirically-driven approach to performance analysis and debugging. I present three systems for performance analysis and debugging. Stabilizer mitigates the performance variability that is inherent in modern processors, enabling both predictable performance in deployment and statistically sound performance evaluation. Coz conducts performance experiments using virtual speedups to create the effect of an optimization in a running application. This approach accurately predicts the effect of hypothetical optimizations, guiding developers to code where optimizations will have the largest effect. Amp allows developers to evaluate system scalability using load amplification to create the effect of high load in a testing environment. In combination, Amp and Coz allow developers to pinpoint code where manual optimizations will improve the scalability of their software

The role of high school GPA and ACT score and its components: a predictor of college success

https://scholarworks.moreheadstate.edu/student_scholarship_posters/1111/thumbnail.jp

An Unusual Antagonistic Pleiotropy in the Penna Model for Biological Ageing

We combine the Penna Model for biological aging, which is based on the mutation-accumulation theory, with a sort of antagonistic pleiotropy. We show that depending on how the pleiotropy is introduced, it is possible to reproduce both the humans mortality, which increases exponentially with age, and fruitfly mortality, which decelerates at old ages, allowing the appearance of arbitrarily old Methuselah's.Comment: 8 pages, 3 figures, to appear in Physica

Fall 1981 Convocation Speech

Fall 1981 Convocation speech given by Dr. Eugene Curtsinger

Buddy Curtsinger One Man Ceramics Exhibition Show Card

Show card for Buddy Curtsinger One Man Ceramics Exhibition. On display was low-fired Raku forms. February 29 - March 13, 1976. Braniff Building.https://digitalcommons.udallas.edu/curtsinger_ceramics/1000/thumbnail.jp

Observations On Structure And Evaluation Of Possible Functions Of The Vexillum In Larval Carapidae (Ophidiiformes)

Elongate dorsal appendages adorn pelagic larvae of many fishes from disparate taxa, among them larvae of the family Carapidae, wherein the singular, elongate appendage is termed a vexillum, The vexillum is a complex larval specialization of the dorsal fin and is characteristic of all carapid genera, It is motile, well vascularized, and innervated by a branch of a cranial nerve with no apparent spinal innervation. Histological studies of Echiodon dawsoni and Carapus bermudensis vexilla show a two layered epidermis with mucous cells, an arteriole and venuole, two myelinated peripheral nerve fascicles, and two collagenous central shafts. No taste buds, free neuromasts or organized chemoreceptors were found on the vexillum, including its fleshy tabs; collateral branches of the nerve fascicles may end as free-nerve endings. In situ observations of living pearlfish larvae revealed a remarkably long and ornamented vexillum that assumed variable postures. The data suggest that carapid vexilla serve multiple functions, including predator deception, sensation, and hydrodynamic effects

Comprehensive honors thesis: Pivot, design of an Oklahoma City youth shelter

The following paper explores the design of a youth shelter in Oklahoma City, expanding on how the design on the building creates a sense of hope, protection, and transition for at-risk youth taken in by Pivot Inc

Positive mutations and mutation-dependent Verhulst factor in Penna ageing model

We twice modify the Penna model for biological ageing. First we introduce back (good) mutations and a memory for them into the model. It allows us to observe an improvement of the species fitness over long time scales as well as punctuated equilibrium. Second we adopt a food/space competition factor that depends on the number of accumulated mutations in the individuals genomes, and get rid of the fixed limiting number of allowed mutations. Besides reproducing the main results of the standard model, we also observe a mortality maximum for the oldest old.Comment: 9 pages, including 3 figures, to be submitted to Physica