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Full-Text Articles in Physical Sciences and Mathematics

Compilation Optimizations To Enhance Resilience Of Big Data Programs And Quantum Processors, Travis D. Lecompte Nov 2022

Compilation Optimizations To Enhance Resilience Of Big Data Programs And Quantum Processors, Travis D. Lecompte

LSU Doctoral Dissertations

Modern computers can experience a variety of transient errors due to the surrounding environment, known as soft faults. Although the frequency of these faults is low enough to not be noticeable on personal computers, they become a considerable concern during large-scale distributed computations or systems in more vulnerable environments like satellites. These faults occur as a bit flip of some value in a register, operation, or memory during execution. They surface as either program crashes, hangs, or silent data corruption (SDC), each of which can waste time, money, and resources. Hardware methods, such as shielding or error correcting memory (ECM), …


Noise Resilience Of Variational Quantum Compiling, Kunal Sharma, Sumeet Khatri2, M. Cerezo, Patrick J. Coles Apr 2020

Noise Resilience Of Variational Quantum Compiling, Kunal Sharma, Sumeet Khatri2, M. Cerezo, Patrick J. Coles

Faculty Publications

Variational hybrid quantum-classical algorithms (VHQCAs) are near-term algorithms that leverage classical optimization to minimize a cost function, which is efficiently evaluated on a quantum computer. Recently VHQCAs have been proposed for quantum compiling, where a target unitary U is compiled into a short-depth gate sequence V. In this work, we report on a surprising form of noise resilience for these algorithms. Namely, we find one often learns the correct gate sequence V (i.e. the correct variational parameters) despite various sources of incoherent noise acting during the cost-evaluation circuit. Our main results are rigorous theorems stating that the optimal variational parameters …


A Spatial Dynamic Model Of Population Changes In A Vulnerable Coastal Environment, Kenan Li Jan 2015

A Spatial Dynamic Model Of Population Changes In A Vulnerable Coastal Environment, Kenan Li

LSU Doctoral Dissertations

Achieving coastal sustainability in low-lying coastal areas is a great challenge. This study developed a spatial dynamic model to study the coupled natural-human responses in the form of population changes in the Lower Mississippi River Basin region. The goal was to identify the key social-economic factors (utility) and selected environmental factors (such as hazards damage, elevation, and subsidence rate) that affect population changes, as well as how population changes affect the local utility and the local environment reciprocally. The study area was partitioned into the “north’ and the “south” by a hypothetical boundary to test the differences of the emergence. …


Community Resilience To Coastal Hazards : An Analysis Of Two Geographical Scales In Louisiana, Chi Li Jan 2013

Community Resilience To Coastal Hazards : An Analysis Of Two Geographical Scales In Louisiana, Chi Li

LSU Master's Theses

Quantifying resilience is difficulties due to the different definitions of resilience, the interchangeable uses with two other terms “vulnerability” and “adaptability”, as well as the lack of consensus on what indicators should be selected to quantifying resilience. This thesis research studied the community resilience in Louisiana by applying the Resilience Inference Measurement (RIM) model at two geographic levels: county level and zip code level. The RIM model accesses resilience by using three dimensions (exposure, damage, and recovery) and two abilities (vulnerability and adaptability). The types of coastal hazards included in this study were: coastal, flooding, hurricane/tropical storm, tornado, and severe …


An Analysis Of The Influences On Household-Level Adaptations To Environmental Hazards, Tiia Maria Carraway Jan 2013

An Analysis Of The Influences On Household-Level Adaptations To Environmental Hazards, Tiia Maria Carraway

LSU Master's Theses

Utilizing a randomized phone survey of coastal Louisiana residents, this study will focus on identifying which influences from a resident’s exposure, socio-economic vulnerability and adaptive capacity are the best indicators of an individual’s resilience. Two binary logistic regression models were developed to test the associations of resident response to: 1) acute hazards via household emergency plan adoption and 2) chronic hazards represented by behavior modification in response to daily air quality reporting where adoption of these two risk-reducing behaviors are viewed as increased individual resilience. Bivariate correlation analysis found that a north – south grouping of coastal Louisiana was significantly …


An Analysis Of The Prevalence Of The West Nile Virus In Relation To Health Resilience Along The Gulf Of Mexico, Lillian Patricia Mata Jan 2013

An Analysis Of The Prevalence Of The West Nile Virus In Relation To Health Resilience Along The Gulf Of Mexico, Lillian Patricia Mata

LSU Master's Theses

As the Earth’s climate changes, coastal communities are increasingly vulnerable to the natural hazards that are driven by these processes, particularly in regards to the health of these communities. It has been shown that disease patterns can change in response to our environment, putting the health resilience of communities at risk. This study looks at the relationship between natural exposure and traditional resilience index variables in the context of the spread of West Nile Virus along the Gulf of Mexico. Through analysis of 534 counties, the West Nile Virus for 2001-2012 was analyzed as an incidence and incidence rate at …


Fish And Macroinvertebrate Assemblage Composition And Diversity At Revetted Banks In The Pearl River And The Response Of These Assemblages To A Paper Mill Effluent Spill, Jose Alexander Vazquez Jan 2013

Fish And Macroinvertebrate Assemblage Composition And Diversity At Revetted Banks In The Pearl River And The Response Of These Assemblages To A Paper Mill Effluent Spill, Jose Alexander Vazquez

LSU Master's Theses

The armoring of river banks with riprap can have detrimental effects on lotic ecosystems due to the subsequent alteration of hydrologic regimes; however, evidence suggests that riprap can also increase aquatic diversity in degraded systems. The goal of my study was to determine what impacts riprapped banks have on fish and macroinvertebrate assemblages in the Pearl River, which has a history of anthropogenic degradation. I collected fishes with an electrofishing boat from armored and natural banks at five regions during fall 2011, winter 2012, and summer 2012. I also collected macroinvertebrates with introduced substrates in fall 2011. Richness was analyzed …


Oligohaline Wetland Response And Recovery Following Storm-Driven Saltwater Intrusion In Coastal Louisiana, Whitney Marie Kiehn Jan 2013

Oligohaline Wetland Response And Recovery Following Storm-Driven Saltwater Intrusion In Coastal Louisiana, Whitney Marie Kiehn

LSU Doctoral Dissertations

Coastal ecosystems occupy an interface between land and ocean, making them vulnerable to a variety of natural and anthropogenic disturbances. Large, episodic disturbances (mega-disturbances) cause immediate and long-lasting changes to coastal wetland plant communities and soils by changing the environmental conditions in which they exist. Here I examined the impacts of storm-induced saltwater intrusion and post-intrusion conditions on the structure and growth of an oligohaline wetland plant community, and on wetland soil biogeochemistry and conditions during and after saltwater intrusion. In the greenhouse, a six-week saltwater intrusion reduced canopy cover and species richness. Once intrusion stress was alleviated, plant community …


Comprehensive Planning And Resilience: A Study Of Louisiana Parishes After Hurricane Katrina, Mary Paille Jan 2012

Comprehensive Planning And Resilience: A Study Of Louisiana Parishes After Hurricane Katrina, Mary Paille

LSU Master's Theses

When hurricanes Katrina and Rita hit in 2005, widespread devastation was felt in over half of the parishes in the state. More than 200,000 homes were damaged and more than 1500 people lost their lives. During this transitionary period, communities were vulnerable and looked for rebuilding leadership. As part of a post-catastrophe resilience movement, the Louisiana Recovery Authority formulated a 50-year regional plan for recovering south Louisiana called Louisiana Speaks. This planning process opened up an opportunity to reach those communities that otherwise may not have considered planning or how it could help them prepare for future events. This places …


Temporal Changes In Quality Of Life And Environment In New Orleans After Hurricane Katrina, Danielle Johanna Larock Jan 2011

Temporal Changes In Quality Of Life And Environment In New Orleans After Hurricane Katrina, Danielle Johanna Larock

LSU Master's Theses

Understanding and assessing the spatial and temporal changes of quality of life and environment of a community is critical to its sustainable development, especially after a disaster strikes. This study explores an approach that integrates remote sensing with socioeconomic data to assess the temporal changes in quality of life and environment (QOL) using Orleans Parish as an example. Hurricane Katrina, which struck New Orleans in 2005, has had vast implications economically, socially, and environmentally for this city and the surrounding area. Empirically quantifying these concepts will help to rebuild the city more sustainably. This study investigated change in environmental quality …


Remediating Impacts Of Global Climate Change-Induced Submergence On Salt Marsh Ecosystem Functions, Camille Lafosse Stagg Jan 2009

Remediating Impacts Of Global Climate Change-Induced Submergence On Salt Marsh Ecosystem Functions, Camille Lafosse Stagg

LSU Doctoral Dissertations

Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment-slurries to increase the elevation of the marsh surface, thus ameliorating the effects of excessive inundation. Although this technique is growing in popularity, the successful restoration of ecological function after sediment addition has received little attention. The purpose of this research was to determine if sediment subsidized salt marshes are functionally equivalent to natural marshes and whether salt marshes …


Resiliency Of New Orleans Following Hurricane Katrina: A Study Of Communities Three Years After The Storm, Lauren Marie Defrank Jan 2009

Resiliency Of New Orleans Following Hurricane Katrina: A Study Of Communities Three Years After The Storm, Lauren Marie Defrank

LSU Master's Theses

In 2005, Hurricane Katrina and subsequent levee failures produced widespread flooding in New Orleans, Louisiana and forced the evacuation of most of the local population. This event allowed for the study of the community’s resilience, or the ability of a system to absorb changes or perturbations and still function. Statistical analysis and case studies were used to study resilience and answer the following questions. Can natural community recovery models be used when evaluating the population recovery of a human community following a disturbance? Given that there are variations in population recovery patterns, what factors account for this difference in recovery? …