Scheduling refinery operation promises a big cut in logistics cost, maximizes efficiency, organizes allocation of material and resources, and ensures that production meets targets set by planning team. Obtaining accurate and reliable schedules for execution in refinery plants under different scenarios has been a serious challenge. This research was undertaken with the aim to develop robust methodologies and solution procedures to address refinery scheduling problems with uncertainties in process parameters. The research goal was achieved by first developing a methodology for short-term crude oil unloading and transfer, as an extension to a scheduling model reported by Lee et al. (1996). The extended model considers real life technical issues not captured in the original model and has shown to be more reliable through case studies. Uncertainties due to disruptive events and low inventory at the end of scheduling horizon were addressed. With the extended model, crude oil scheduling problem was formulated under receding horizon control framework to address demand uncertainty. This work proposed a strategy called fixed end horizon whose efficiency in terms of performance was investigated and found out to be better in comparison with an existing approach. In the main refinery production area, a novel scheduling model was developed. A large scale refinery problem was used as a case study to test the model with scheduling horizon discretized into a number of time periods of variable length. An equivalent formulation with equal interval lengths was also presented and compared with the variable length formulation. The results obtained clearly show the advantage of using variable timing. A methodology under self-optimizing control (SOC) framework was then developed to address uncertainty in problems involving mixed integer formulation. Through case study and scenarios, the approach has proven to be efficient in dealing with uncertainty in crude oil composition.

This dissertation has three contributions in the area of path planning for Unmanned Aerial Vehicle (UAV) Search And Track (SAT) missions. These contributions are: (a) the study of a novel metric, G, used to quantify the value of the target information gained during a search and track mission, (b) an optimal planning horizon that minimizes time-error of a planning horizon when interrupted by Poisson random events, and (c) a modified Particle Swarm Optimization (PSO) algorithm for search missions that uses the prior target distribution in the generation of paths rather than just in the evaluation of them. UAV route planning is an important topic with many applications. Of these, military applications are the best known. This dissertation focuses on route planning for SAT missions that jointly optimize the conflicting objectives of detecting new targets and monitoring previously detected targets. The information theoretic approach proposed here is different from and is superior to existing approaches. One of the main differences is that G quantifies the value of the target information rather than the information itself. Several examples are provided to highlight G’s desirable properties. Another important component of path planning is the selection of a planning horizon, which specifies the amount of time to include in a plan. Unfortunately, little research is available to aid in the selection of a planning horizon. The proposed planning horizon is derived in the context of plan updates triggered by Poisson random events. To our knowledge, it is the only theoretically derived horizon available making it an important contribution. While the proposed horizon is optimal in minimizing planning time errors, simulation results show that it is also near optimal in minimizing the average time needed to capture an evasive target. The final contribution is the modified PSO. Our modification is based on the idea that PSO should be provided with the target distribution for path generation. This allows the algorithm to create candidate path plans in target rich regions. The modified PSO is studied using a search mission and is used in the study of G.

In the tradition of academic satire, Lady Lazarus is the fictional biography of the daughter of American rock musicians. In her late teens she rises to fame as confessional poet, who, despite only publishing one collection of poems during her brief life, becomes an overnight sensation. Author Andrew Altschul is satirizing academia’s need to be a part of popular culture and in doing so, privileges the ability to use controversy and conventional beauty to sell books as opposed to creating quality art. By focusing on how the author uses Hans Robert Jauss’ horizons of expectations, unreliable narrators, anecdotes in biography and the economics of fame as a deciding factor in academia, the author has created a dense and punitive opinion of academia’s inclusion of popular culture into its world.

The behavior of Deepwater Horizon crude oil and other sources of oil were investigated when exposed to sunlight in aquatic systems under environmentally relevant conditions. This research decoupled the abiotic and biotic weathering modifications of oil by focusing solely on the photochemical transformations of oil in aquatic systems. Photochemical rates and mechanisms were measured through the determination of reactive transients. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. Titanium dioxide (TiO2) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. Photochemical production of singlet oxygen from thin oil films over seawater and pure water was measured with furfuryl alcohol as a selective chemical probe. The loss of furfuryl alcohol and the formation of 6-hydroxy(2H)pyran-3(6H)-one were monitored. Photochemical production of organic triplets from 6 different compositions of petroleum was measured through the cis-trans isomerization of 1,3 pentadiene in Gulf water. The data correlate very well with previously measured singlet oxygen concentrations. The energies were measured in the range of 280-300 kJ/mol. Macondo Well Oil from the Deepwater Horizon (DWH) rig was mixed with pure water and seawater and irradiated with simulated sunlight. After irradiation, the water-soluble organics (WSO) from the dark and irradiated samples were extracted and characterized by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Liquid-liquid extraction yielded two fractions from dark and irradiated water/oil mixtures: acidic WSOs (negative-ion electrospray (ESI)), and base/neutral WSOs (positive-ion ESI). These fractions were analyzed by FT-ICR MS to catalogue molecular-level transformations that occurred to oil-derived WSOs after solar irradiation. The increased abundance of higher-order oxygen classes in the irradiated samples relative to the dark samples indicates that photooxidized components of the Macondo crude oil become water-soluble after irradiation. Time series studies were performed to observe the changes in WSO composition. The predominance of higher-order oxygen classes indicates that multiple photochemical pathways exist that result in oxidation of petroleum compounds. More oxygenated compounds were observed in the WSO acid fraction of oils with higher API gravity.

O projeto de estratégias de controle preditivo (MPC) com estabilidade garantida, que incorpora explicitamente a incerteza de modelo na formulação de controle, ainda permanece uma questão em aberto na literatura, embora uma ampla teoria já tenha sido desenvolvida para a síntese de algoritmos MPC robustamente estáveis. Em verdade, as soluções existentes para o problema de MPC robusto estão longe de uma etapa aceitável de implementação prática, principalmente se o sistema de processo é composto de modos integradores ou instáveis, e também apresenta atrasos de tempo (tempos mortos) entre suas variáveis de entrada e saída. Sob esta perspectiva, o objetivo principal desta tese é desenvolver uma estrutura de síntese de controladores MPC com estabilidade robusta garantida para sistemas de processo com as características integradoras ou instáveis, assim como tempos mortos entre as variáveis. Particularmente, três diferentes estratégias de MPC robusto são desenvolvidas neste trabalho. As duas primeiras referem-se a sistemas integradores com tempos mortos: o primeiro algoritmo é baseado em uma formulação de controle em dois passos, enquanto o segundo é posto como um problema de otimização de controle em um passo e a representação de modelo em variáveis de estado é mais geral do que aquela adotada na formulação do primeiro método. A terceira estratégia proposta focaliza os sistemas instáveis com tempos mortos através de uma formulação de controle em um passo. Ademais, visando o caso de implementação prática, os controladores desenvolvidos compreende os seguintes aspectos: (i) as leis de controle livre de erro permanente são obtidas sem a necessidade de incluir uma camada de otimização adicional de cálculo de estados estacionários, devido à formulação adequada de modelos em espaço de estados na forma incremental das entradas, os quais são derivados de expressões analíticas de resposta ao degrau do sistema de processo; (ii) a incerteza de todos os parâmetros do modelo, e.g. ganhos, constantes de tempo, atrasos de tempo, é considerada na formulação do problema; (iii) as provas de estabilidade robusta segundo Lyapunov são realizadas de uma forma intuitiva através da imposição de restrições terminais de igualdade e restrições de contração de custo; (iv) a inclusão adequada de variáveis de folga, que não comprometem as propriedades estabilizantes dos controladores, assegura que os problemas de otimização são sempre viáveis; (v) integração estável com camada de otimização em tempo real, visto que os controladores são projetados de tal forma a rastrear targets ótimos para algumas entradas e saídas do processo, mantendo as variáveis remanescentes dentro de faixas pré-definidas, ao invés de set-points xos. Exemplos de simulação típicos da indústria de processo são explorados para ilustrar as potenciais utilidades dos métodos propostos e demonstrar que eles podem ser aplicados em casos reais. / The design of stable model predictive control (MPC) strategies that explicitly incorporate the model uncertainty into the control formulation still remains an open issue, although a rich theory has been developed to the synthesis of robustly stabilizing MPC schemes. In fact, the existing solutions to the robust MPC problem seem far from an acceptable stage of practical imple mentations, chiey when the process system is composed of integrating and unstable poles, as well as time delays between its input and output variables. Within this perspective, the ultimate goal of this thesis is to develop a new framework for robust MPC synthesis which guarantees closed-loop stability of integrating and unstable time delay processes. On this subject, three different robust MPC strategies are developed. The two rst concerns on integrating time delay processes; the former is based on a two-step control formulation, whereas the latter is posed as a one-step control optimization problem and state-space model description is more general than that adopted in the former formulation. The third proposed strategy focuses on one-step control formulation-based unstable time delay processes. Aiming at practical implementation purposes, the controllers proposed herein comprise the following aspects: (i) the offset free control laws are obtained without the need to include an additional steady-state calculation op timization layer due to the enclosure of proper state-space models in the incremental form of the inputs, which are derived of analytical expressions of step response of the process system; (ii) the uncertainty of all model parameters, e.g. gains, time constants, time delays and so on, is considered in the problem formulation; (iii) the proofs of robust Lyapunov stability are easily carried out of an intuitive way by imposing terminal equality constraints and cost-contracting constraints; (iv) the suitable inclusion of slack variables, which does not commit the stabil ity properties of the controllers, ensure that the proposed optimization problems are always feasible; (v) stable integration with real-time optimization layer, seeing as the controllers are designed to work in the optimum target tracking scheme where they should drive the process to the optimum operating point, while maintaining the remaining inputs and outputs inside pre dened zones instead of xed set-points. Simulation examples typical of the process industry are exploited to illustrate the helpfulness of the proposed control methods and demonstrate that they can be implemented in real applications.

O presente estudo investigou se o uso do lucro econômico em contratos de incentivo contingentes ao desempenho motiva os indivíduos a agir de forma mais consistente com os objetivos de longo prazo da empresa quando existe o problema do horizonte. Para tanto, foi utilizado um experimento de fator único entre sujeitos, pré-pós tratamento com grupo de controle, cuja única tarefa dos participantes era investir recursos em ações de longo prazo visando maximizar o fluxo de caixa futuro de uma loja de prestação de serviço. O estudo envolveu a participação de 76 estudantes de graduação, divididos em três grupos, e documentou que, em comparação ao grupo de controle (recompensado com base numa remuneração fixa) e a um segundo grupo de tratamento (recompensado com base numa remuneração variável vinculada ao lucro contábil contemporâneo), os participantes submetidos ao contrato que recompensava com base no lucro econômico agiram de forma mais congruente em relação ao objetivo estabelecido, dedicando mais esforço na realização da tarefa e melhorando o desempenho nas suas decisões de investimentos. Consistente com as predições da teoria da agência, o principal resultado dessa investigação sugere que o lucro econômico ajuda a mitigar o problema de miopia gerencial, indicando que incorporá-lo aos contratos motiva os agentes a agir de forma mais consistente com os objetivos de longo prazo da empresa, mesmo na presença do problema do horizonte. Além disso, a pesquisa documentou novas evidências da inadequação da formulação de contratos de incentivo baseados em medidas de desempenho distorcidas, tal como o lucro contábil. / The present study investigated whether the use of economic profit in performance-contingent incentive contracts motivates individuals to act more consistently with the long-term goals of the firm when the horizon problem is present. An experimental design was conducted. The experiment used a single factor between-subjects and pre-post treatment with a control group. The experimental task was to invest resources in long-term actions with the goal of maximizing the future cash flow of a photocopy store. The study involved the participation of 76 undergraduate students, divided into three groups, and documented that participants rewarded by contracts based on economic profit acted more congruently with the goal set by devoting more effort to accomplish the task and improving performance in their investment decisions when compared to the control group (rewarded on the basis of a fixed wage) and to the second treatment group (rewarded on the basis of a contingent contemporaneous accounting profit incentive contract). The present study\'s key findings are consistent with the predictions of the agency theory and suggest that the economic profit helps to mitigate the problem of managerial myopia. These study findings also indicate that the economic profit in incentive contracts motivates agents to act more consistently with the firm\'s long-term goals even in the presence of the horizon problem. In addition, the present research documented new evidences of the inadequacy of incentive contracts based on distorted performance measures such as accounting profit.

A thermal is a column of warm rising air triggered by differential heating on the ground. In recent studies UAVs were programmed to exploit this free atmospheric energy from thermals to improve their range and endurance. Researchers had successfully flown UAVs autonomously with thermal soaring method. Most research involved some form of flight simulation. Improvements to the aircraft and thermal models for simulation purpose would enable researchers to better design their UAVs and explore any potential flaws in their designs. An aircraft simulation with a thermal environment was created in Horizon Simulation Framework, a modeling and verification framework that was developed by Cal Poly Space Technologies and Applied Research laboratory. The objective of this study is to enhance the fidelity of existing modeling and simulation methods on autonomous thermal soaring, and to advance and demonstrate the capabilities of Horizon Simulation Framework through such implementation. The geometry of a small remote controlled glider was used in this simulation. Aerodynamic prediction programs DATCOM+ and AVL were used to obtained stability and control derivatives for this glider. The induced roll effect caused by the asymmetric vertical velocity distribution of a thermal was included in the aerodynamic roll moment calculation. The autonomous guidance algorithm for the glider included a turn logic which would determine the correct turn direction for the glider when a thermal is detected. The thermal model developed in this thesis included the capabilities to vary the time dependent location, height, radius, and vertical velocity characteristics of naturally occurring thermals.

Simulated oil spills were created in S. alterniflora sediment-water microcosms to determine the effects of applied crude oil on S.alterniflora during two 90-day studies. In the first experiment, oil dosage was varied at 0-250 mg crude oil/g wet soil to determine the lethal dosage level. In the second experiment, oil type, dosage, and soil type were varied to determine the effects of oil under multiple scales of resolution. A light, medium, and heavy crude oil at dosages ranging from 0-150 mg crude oil/g wet soil were used in addition to an oiled and non-oiled soil. Following the completion of the 90-day experiment, several key findings were observed: (1) The lethal dosage limit was reached at 250 mg crude oil/g wet soil during the first experiment but not the second, by design; (2) At initial dosages of 10 and 50 mg crude oil/g wet soil, the oiled soil (acclimated for 4 months) was more influential in decreasing cumulative biomass growth rates compared to oil applied at the oil-water interface; (3) At the heaviest dosages applied as a simulated oil slick, concentrations of 150 mg crude oil/g wet soil, evapotranspiration rates were negatively affected by the oil (significant at p=0.05 in a one-tailed t-test); (4) Light, heavy, and then medium crude oil showed the lowest biomass growths, in that order, indicating that light crude oil was the most toxic in these microcosm experiments with S. alterniflora; (5) The 10 mg oil/g wet soil out-performed the 0 mg oil/g wet soil in transpiration and biomass growth.

The goal of the research conducted in this dissertation was to define and test methods to incorporate oil spill effects into an ecosystem-based assessment model. It was instigated by the Deepwater Horizon oil spill, an unprecedented oil spill in the United States for both depth and volume, with unknown implications for the health of the region. Using an ecosystem-based assessment model like Atlantis, with integrated oil spill dynamics, was the ideal candidate to predict long-term impacts such as decreased abundance or population recovery time. However no previous methodology existed for doing so in any ecosystem-based assessment model. Therefore, first I conducted a literature review to gather data across fish species on lesion frequency and fish body growth impacts from oil exposure. The two data sets were then fitted to four different dose-response models, and an effect threshold log-linear “hockey-stick” model was selected as the best fit and most parsimonious for both lesions and growth. Next, I conducted a similar analysis comparing macrofaunal and meiofaunal abundances to oil exposure concentrations in the Gulf of Mexico collected after Deepwater Horizon. I confirmed that these data had the domed relationship between invertebrate abundances and oil concentration observed in previous invertebrate oil studies. This domed relationship indicates that abundance increases at low to moderate oil levels, and declines at high oil levels. To drive this relationship in an Atlantis ecosystem model, three scenarios were tested in combination with oil toxicity: 1) Mississippi nutrient loading, 2) increased detritus from marine oil snow sedimentation and flocculent accumulation, and 3) predators altering their behavior to avoid oil exposure. At the Atlantis polygon resolution, only scenario 2, increased detritus from marine oil snow sedimentation and flocculent accumulation, generated the domed relationship for invertebrate abundances. Lastly, the “hockey-stick” model for fish mortality and growth was applied to both fishes and invertebrates in combination with scenario 2 for an integrated long-term assessment of the Gulf of Mexico. Newly available fish exposure data were used to generate an uptake-depuration model for this assessment. The combined effect forcings on vertebrates and invertebrates proved to have more severe long-term implications on population size and recovery than simulations with only fish forcings. Large demersal fishes, including elasmobranchs, were the most severely impacted by large biomass declines in the model spill region. Sensitivity analyses indicated that there was the potential for no recovery during 50 years of simulation in the spill region for many functional groups. Analysis of the synergy between fishing mortality F and toxicity from an oil spill identified that some guilds are more sensitive in an oil spill simulation to varied F than others. Snappers are the most sensitive to increased fishing mortality, while groupers respond the most to a reduction in fishing mortality. The invertebrate guild and small pelagic fishes responded the least to different values of F. Changing F also had implications for guild recovery – some guilds only fully recovered to control scenario biomass when F was reduced. A few functional groups were unable to survive with the combined effects of oil toxicity and increased F, and went extinct before the end of the 50-year simulation. Overall, this work provided the first framework for initial integrated modeling of oil spill impacts in an ecosystem-based assessment model, a potentially important component to future ecosystem-based fisheries management. The “hockey-stick” dose response model is applicable beyond Atlantis modeling, and can be tuned to fit specific events based on available data. I have also identified the importance of including marine oil snow sedimentation and flocculent accumulation to accurately drive the response of benthic invertebrates. Findings from the combined vertebrate and invertebrate simulations should help inform research efforts in the Gulf of Mexico and future oil spill response efforts.

Cytokines are pleiotropic and redundant signaling molecules that govern the inflammatory response and immunity, a critical ecological parameter for organism success and population growth. Produced at the site of injury or pathogen intrusion by a variety of cell types, cytokines mediate cell-signaling in either an autocrine or paracrine manner. The type and magnitude of the cytokine milieu produced subsequently dictates the strength and form of immune response. As the most diverse vertebrate group, with a high sensitivity to contaminants, fish represent an important foci for the evaluation of immune system evolution, function, and alteration upon toxicant exposure. While many cytokines have been identified in teleosts, primary study has been limited to model species (e.g. zebrafish and fugu). However, evidence exists for several variations of cytokine genes within taxa, underscoring the need for species-specific evaluation. In this study, two pro-inflammatory cytokines (IL-1β and TNFα ), one chemokine (IL-8), and one anti-inflammatory cytokine (IL-10) were cloned, sequenced, and characterized for the first time in two commercially relevant Perciformes in the Gulf of Mexico, golden tilefish (Lopholatilus chamaeleonticeps) and red snapper (Lutjanus campechanus). The complete amino acid sequence was obtained and confirmed for IL-β and IL-8 from golden tilefish and for IL-8, IL-10, and TNFα from red snapper, with partial sequences obtained for the remaining proteins. The results indicate high homology among Perciformes for all cytokines studied, but divergence with other teleost orders, and low conservation when compared to birds, amphibians, and mammals. The sequences will be used to create a multi-plexed antibody-based assay for the routine detection of cytokines in teleost serum. This would allow the biochemical response to fish health challenges, such as oil spills and other contamination events, to be monitored at the protein level, building upon the current regime of genetic biomarkers. Thus, this work will aid in the understanding of how oil spills and other contamination events may alter the immune response in fishes.