Development of a Quasi-Monte Carlo Method for Thermal Radiation

Radiative heat transfer in participating media is among the most challenging computational engineering problems due to the complex nonlinear, nonlocal nature of radiation transport. Many approximate methods have been developed in order to resolve radiative heat transfer in participating media; but approximate methods, by the nature of their approximations, suffer from various shortcomings both in terms of accuracy and robustness. The only methods that can resolve radiative transfer accurately in all configurations are the statistical Monte Carlo-based methods. While the Monte Carlo (MC) method is the most accurate method for resolving radiative heat transfer, it is also notoriously computationally prohibitive in large-scale simulations. To overcome this computational burden, this study details the development of a quasi-Monte Carlo (QMC) method for thermal radiation in participating media with a focus on combustion-related problems. The QMC method employs a low-discrepancy sequence (LDS) in place of the traditional random number sampling mechanism used in Monte Carlo methods to increase computational efficiency. In order to analyze the performance of the QMC method, a systematic comparison of accuracy and computational expense was performed. The QMC method was validated against formal solutions of radiative heat transfer in several one-dimensional configurations and extended to three practical combustion configurations: a turbulent jet flame, a high-pressure industrial gas turbine, and a high-pressure spray combustion chamber. The results from QMC and traditional Monte Carlo are compared against benchmark solutions for each case. It is shown that accuracy of the predicted radiation field from QMC is comparable to MC at lower computational costs. Three different low-discrepancy sequences – Sobol, Halton, and Niederreiter – were examined as part of this work. Finally, recommendations are made in terms of choice of the sequence and the number of the dimensions of the LDS for combustion-relevant configurations. In conclusion, significant improvements in computational costs and accuracy seen in the QMC method makes it a viable alternative to traditional Monte Carlo methods in high-fidelity simulations

The Socioeconomic Impact of the Mountain Parkway and KY 15

A study of socioeconomic variables in a nine-county region in Eastern Kentucky was undertaken to determine whether significant growth had occurred since the opening of the Mountain Parkway and reconstruction of KY 15. It was hypothesized that these roads have acted as catalysts with available resources to promote a better quality of life. Study revealed that, while income levels and business sales have enjoyed substantial increases, overall quality of life is still poor. Educational facilities are inadequate; economic diversification in business types is limited; coal is still the main stimulant for income and employment. However, outmigration of persons from the area has been reversed simply because economic conditions are better due to the reemergence of coal. Since the return of coal as a more important energy resource for the nation has only occurred recently, the full impact of the energy crisis and better highways has yet to be seen in regard to socio-economic stimulation of this traditionally depressed region

One or Two Things I Know About Us: Narrative Strategies for Autoethnography, Self-Representation and Healing in Four Memoirs by Poor-white Women from the U.S. South

This dissertation examines autobiographical writings by formerly poor white Southern women, who are rarely considered as a group and are more typically studied with “rough South” male writers, which would suggest that few women have contributed their own gendered experience to discussions of class, race, and sexuality vis-à-vis Southern poverty. Correcting this assumption, I examine formative statements by women from poor white backgrounds, including Roxanne Dunbar-Ortiz’s Red Dirt, Janisse Ray’s Ecology of a Cracker Childhood and Wild Card Quilt, Dorothy Allison’s Trash, and Jeannette Walls’s The Glass Castle. Each of these writers engage in narrative strategies that do not defend a violent, masculinist Southern culture from misrepresentation by outsiders, as do male “redneck autobiographers,” but rather re-establish connections with their families, native communities, and natural environments. In the process of writing on Okies, Crackers, and “white trash,” these writers describe their transition from concealing the truth about their families out of shame to considering them autoethnographically. Autoethnography provides the methodology by which Dunbar-Ortiz, Ray, Allison and Walls write about their personal lifeworlds, a concept from phenomenology that considers the body as the locus of one’s natural, social, and cultural environment. In explicating their memoirists’ most salient themes, I employ concepts by theorists in the phenomenological tradition, including Edmund Husserl, Jurgen Habermas, R. D. Laing, Pierre Bourdieu, and Francisco Varela, who all recommend a practice of self-observation as a kind of “portable laboratory” for investigating the intersections of embodiment, habit, and history. I conclude that the self-knowledge gained through such a practice enables each of the women in this study to find a voice in the place where she had not had one, and to write authoritatively about her respective Southern culture

Lack of continuity between Cronobacter biotypes and species as determined using multilocus sequence typing

The accuracy of the Cronobacter biotyping scheme was compared with the 7-loci multilocus sequence typing scheme. Biotyping did not reliably assign species level identification, as only half (17/31) of the biotype variants were unique to any of the seven Cronobacter species and the remaining biotypes were shared across the genus

An Efficient Monte Carlo-Based Solver for Thermal Radiation in Participating Media

Monte Carlo-based solvers, while well-suited for accurate calculation of complex thermal radiation transport problems in participating media, are often deemed computationally unattractive for use in the solution of real-world problems. The main disadvantage of Monte Carlo (MC) solvers is their slow convergence rate and relatively high computational cost. This work presents a novel approach based on a low-discrepancy sequence (LDS) and is proposed for reducing the error bound of a Monte Carlo-based radiation solver. Sobols sequence – an LDS generated with a bit-by-bit exclusive-or operator – is used to develop a quasi-Monte Carlo (QMC) solver for thermal radiation in this work. Preliminary results for simple radiation problems in participating media show that the QMC-based solver has a lower error than the conventional MC-based solver. At the same time, QMC does not add any significant computational overhead. This essentially leads to a lower computational cost to achieve similar error levels from the QMC-based solver than the MC-based solver for thermal radiation

Before Evaluation of Economic Growth Center Developmental Highway (US 25E: Corbin-Barbourville)

Before-and-after impact studies were selected as the means of determining the effect of reconstructing a 4.886 mile (7.862 kilometer) section of US 25E between Corbin and Barbourville. A comprehensive analysis of the before statistics revealed the area designated as a potential growth center suffered from social and economic mediocrity. Many characteristics considered essential for economic prosperity are lacking. Per capita income and educational achievement levels are lower than statewide averages. Transportation is dependent upon highways and many existing routes provide a very low level of service. On the other hand, the area has adequate industrial and recreational potential to insure economic growth when the appropriate factors are combined. It was hypothesized that reconstruction of the section of highway would encourage economic growth and provide a general upgrading of the standard of living in the area. This could be the first step in reversing the basic out-migration problem and would, in the long run, create a means for encouraging a more balanced population pattern in the urbanized sections of the nation

Before Evaluation of Economic Growth Center Developmental Highway (KY 55, Campbellsville-Lebanon)

Before-and-after impact studies were selected as the means of determining the effect of reconstructing a 4.813-mile (7.744-kilometer) section of KY 55 between Campbellsville and Lebanon. The area, though still depressed in terms of per capita income and employment, has many resources available for growth. The study area is predominantly an agriculturally-oriented economy. However, manufacturing employment has increased in recent years, mainly because of industrial sites made available by local industrial commissions. Overall, social services appear to be adequate and very near statewide averages. Recreational facilities are not highly developed and are primarily of the summer outdoor type. Reconstruction of KY 55 could bring about economic growth which may affect the standard of living within the target area. Increased accessibility and attractiveness of the area could increase the rural-to-urban population ratio which has been adversely unbalanced by the migration from rural to urban areas

A Slow Growing Verrucous Plaque on the Scalp

A 73 year-old Caucasian male with a history of multiple non-melanoma skin cancers presented to dermatology for evaluation of a growth on the left scalp. He endorsed that the lesion had been present for many years but was slowly growing larger and thicker and had recently bled spontaneously and become intermittently painful. The lesion had been evaluated several times over a span of 3 years and was previously thought to most likely represent a verrucous seborrheic keratosis. The patient was otherwise in a good state of health and had no known history of immunosuppression.On the left parietal scalp there was a pink-brown verrucous plaque with filiform projections and focal hemorrhagic crust. The lesion measured 5.2 cm x 3.8 cm.Saucerization biopsy of the most exophytic portion of the lesion was performed and revealed a broad, atypical melanocytic proliferation within a larger verrucous keratosis with features consistent with a ‘verrucous pseudonevoid melanoma of the scalp. The Breslow depth was measured at 1mm.The patient was treated with a wide local excision with 1 cm margins. The re-excision specimen showed focal residual melanoma in-situ and clear margins. A sentinel lymph node biopsy was performed for staging and was found to be negative for metastatic disease.Nevoid melanoma is a rare entity which presents diagnostic difficulty on both clinical and histopathological grounds. On physical examination this tumor can be mistaken clinically for a verruca, benign melanocytic or epidermal nevus, or seborrheic keratosis. There are two major architectural variants: verrucous subtype and a dome-shaped variant (resembles a Meissner or Spitz nevus). The verrucous-subtype (as seen in our case) has been reported to have the following features which may distinguish it from a papillomatous nevus: (1) broad, exophytic growth pattern with a verrucous epidermal hyperplasia, (2) continuous proliferation of melanocytes along the dermal-epidermal junction, (3) confluent sheets of uniform, monomorphic without evidence of true maturation, and (4) occasional dermal mitoses.Mortality related to nevoid melanomas is thought to be consistent with that of traditional melanomas of the same Breslow depth. However, nevoid melanomas are commonly more advanced at the time of diagnosis given propensity for initial clinical and/or histologic misdiagnosis. Therefore, heightened awareness of this entity is critical to better ensure earlier diagnosis.https://scholarlycommons.henryford.com/merf2019caserpt/1011/thumbnail.jp

Court of Public Opinion in and for the State of Uncertainty

Our session has two goals. First, we aim to stimulate debate over a ubiquitous, yet largely unchallenged, instrument that purports to operationalize Jungian personality theory (the Myers-Briggs Type Indicator). Second, we suggest a platform for teaching management theories, the mock-trial, which manifests active learning as well as critical thinking and has been successfully utilized in other disciplines. With contributors playing key roles in the trial and volunteers from the audience serving as potential prosecution and defense witnesses as well as the jury, we hope the discourse on substantive theory and teaching process will provide the jolt OBTC 2008 envisions