Tanenbaum, Trenk, and Fishburn introduced the concept of linear discrepancy in 2001, proposing it as a way to measure a partially ordered set's distance from being a linear order. In addition to proving a number of results about linear discrepancy, they posed eight challenges and questions for future work. This dissertation completely resolves one of those challenges and makes contributions on two others. This dissertation has three principal components: 3-discrepancy irreducible posets of width 3, degree bounds, and online algorithms for linear discrepancy. The first principal component of this dissertation provides a forbidden subposet characterization of the posets with linear discrepancy equal to 2 by completing the determination of the posets that are 3-irreducible with respect to linear discrepancy. The second principal component concerns degree bounds for linear discrepancy and weak discrepancy, a parameter similar to linear discrepancy. Specifically, if every point of a poset is incomparable to at most D other points of the poset, we prove three bounds: the linear discrepancy of an interval order is at most D, with equality if and only if it contains an antichain of size D; the linear discrepancy of a disconnected poset is at most the greatest integer less than or equal to (3D-1)/2; and the weak discrepancy of a poset is at most D. The third principal component of this dissertation incorporates another large area of research, that of online algorithms. We show that no online algorithm for linear discrepancy can be better than 3-competitive, even for the class of interval orders. We also give a 2-competitive online algorithm for linear discrepancy on semiorders and show that this algorithm is optimal.

The depositional styles of sediment gravity currents depend, in part, on the relationship of flow magnitude to the scale of topographically controlled containment and range from unconfined lobes to fully contained deposits. Determining the degree of containment is important for understanding depositional processes, land to ocean sediment transfer and subsurface reservoir characterization/prediction. Depositional models of the fully contained (commonly referred to as 'ponded') end member have been developed (e.g. fill-and-spill model). However, fully contained deposits represent only a portion of deepwater deposits and little work has been done identifying and examining the degree of containment of the more complex, partially contained deposits in outcrop. Here, I document the sedimentological facies and stratigraphic architecture of the Zorrillo Unit, a partially contained system exposed at Cerro Solitario within the Upper Cretaceous Tres Pasos Formation of the Magallanes Basin. The evolution of partial containment at this outcrop is expressed as: 1) bypass in the proximal zone and flow stripping in the distal zone, 2) backstepping and blanketing of the outcrop, followed by 3) renewed bypass. The partially contained system at Cerro Solitario deviates from the widely used fill-and-spill model due to subtle relief. This record of infilling provides insight into the overall evolution of the depositional system. Within the Magallanes Basin, the partially contained and linked depocenters along the Chingue Clinoform represent the dying breaths of the Cerro Toro axial conglomerate channel system as the canyon-fed point source collapsed and choked off the sediment routing system out to the distal basin. / Master of Science

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This student thesis in General Management addresses how leaders can bridge the gap between work groups and teams in geographically dispersed organizations and partially distributed teams. These types of organizational structures are increasingly common in the globalized world of business, and bring benefits to many organizations by for example connecting skilled workers regardless of their location through the means of information and communications technology. However, previous research within the field of work in dispersed settings has identified several challenges that these settings entail, including areas like for example group cohesion and motivation. If not handled, these challenges may have negative effects on team performance and organizational effectiveness. Previous studies have mostly targeted the challenges in isolation. The purpose of this study is to provide a holistic perspective, connecting different challenges in order to pinpoint reasons and effects. By identifying consequences that follow from being geographically dispersed and investigating how the challenges affect a real-world organization, the study aims to suggest countermeasures to deal with these consequences. Theory is built using Informed Grounded Theory, based on primary data from 21 in-depth interviews conducted at a Swedish high tech company. Through an analysis combining the primary data with secondary data stemming from relevant literature, the study presents conclusions including suggested countermeasures to overcome challenges imposed by work in dispersed settings. The study identifies communication as the key factor with possibility to affect group cohesion and motivation directly, and thereby also performance indirectly. Thoughtful use of different types of communication can in fact counteract challenges and lead to increased productivity and well-being. The study has implications for organizations that are planning for, or currently utilizing a dispersed organizational structure, and aids in understanding the collected effects of the challenges involved. The study is conducted at one company, which can be seen as a limitation. To counteract for this limitation, the researchers have put in effort to emphasize generalizable factors.

A large eddy simulation (LES) model has been developed and validated for turbulent non-premixed and partially premixed combustion systems. LES based combustion modelling strategy has the ability to capture the detailed structure of turbulent flames and account for the effects of radiation heat loss. Effects of radiation heat loss is modelled by employing an enthalpy-defect based non-adiabatic flamelet model (NAFM) in conjunction with a steady non-adiabatic flamelet approach. The steady laminar flamelet model (SLFM) is used with multiple flamelet solutions through the development of pre-integrated look up tables. The performance of the non-adiabatic model is assessed against experimental measurements of turbulent CH4/H2 bluff-body stabilized and swirl stabilized jet flames carried out by the University of Sydney combustion group. Significant enhancements in the predictions of mean thermal structure have been observed with both bluff body and swirl stabilized flames by the consideration of radiation heat loss through the non-adiabatic flamelet model. In particular, mass fractions of product species like CO2 and H2O have been improved with the consideration of radiation heat loss. From the Sydney University data the HM3e flame was also investigated with SLFM using multiple flamelet strategy and reasonably fair amount of success has been achieved. In this work, unsteady flamelet/progress variable (UFPV) approach based combustion model which has the potential to describe both non-premixed and partially premixed combustion, has been developed and incorporated in an in-house LES code. The probability density function (PDF) for reaction progress variable and scalar dissipation rate is assumed to follow a delta distribution while mixture fraction takes the shape of a beta PDF. The performance of the developed model in predicting the thermal structure of a partially premixed lifted turbulent jet flame in vitiated co-flow has been evaluated. The UFPV model has been found to successfully predict the flame lift-off, in contrast SLFM results in a false attached flame. The mean lift-off height is however over-predicted by UFPV-δ function model by ~20% for methane based flame and under-predicted by ~50% for hydrogen based flame. The form of the PDF for the reaction progress variable and inclusion of a scalar dissipation rate thus seems to have a strong influence on the predictions of gross characteristics of the flame. Inclusion of scalar dissipation rate in the calculations appears to be successful in predicting the flame extinction and re-ignition phenomena. The beta PDF distribution for the reaction progress variable would be a true prospect for extending the current simulation to predict the flame characteristics to a higher degree.

In applying reinforcement learning to agents acting in the real world we are often faced with tasks that are non-Markovian in nature. Much work has been done using state estimation algorithms to try to uncover Markovian models of tasks in order to allow the learning of optimal solutions using reinforcement learning. Unfortunately these algorithms which attempt to simultaneously learn a Markov model of the world and how to act have proved very brittle. Our focus differs. In considering embodied, embedded and situated agents we have a preference for simple learning algorithms which reliably learn satisficing policies. The learning algorithms we consider do not try to uncover the underlying Markovian states, instead they aim to learn successful deterministic reactive policies such that agents actions are based directly upon the observations provided by their sensors. Existing results have shown that such reactive policies can be arbitrarily worse than a policy that has access to the underlying Markov process and in some cases no satisficing reactive policy can exist. Our first contribution is to show that providing agents with alternative actions and viewpoints on the task through the addition of active perception can provide a practical solution in such circumstances. We demonstrate empirically that: (i) adding arbitrary active perception actions to agents which can only learn deterministic reactive policies can allow the learning of satisficing policies where none were originally possible; (ii) active perception actions allow the learning of better satisficing policies than those that existed previously and (iii) our approach converges more reliably to satisficing solutions than existing state estimation algorithms such as U-Tree and the Lion Algorithm. Our other contributions focus on issues which affect the reliability with which deterministic reactive satisficing policies can be learnt in non-Markovian environments. We show that that greedy action selection may be a necessary condition for the existence of stable deterministic reactive policies on partially observable Markov decision processes (POMDPs). We also set out the concept of Consistent Exploration. This is the idea of estimating state-action values by acting as though the policy has been changed to incorporate the action being explored. We demonstrate that this concept can be used to develop better algorithms for learning reactive policies to POMDPs by presenting a new reinforcement learning algorithm; the Consistent Exploration Q(l) algorithm (CEQ(l)). We demonstrate on a significant number of problems that CEQ(l) is more reliable at learning satisficing solutions than the algorithm currently regarded as the best for learning deterministic reactive policies, that of SARSA(l).

Anxiety levels of partially sighted were compared with totally blind people. Using the Anxiety Scale for the Blind, the primary hypothesis tested was that the partially sighted would manifest more anxiety than would the totally blind. The study was designed to ascertain whether the primary hypothesis would hold within the structure of this study, and to obtain information useful in future anxiety studies of the visually handicapped. A residential center for the blind furnished subjects, facilities, and biographical data. The primary hypothesis lacked statistical significance at the .05 level as did comparisons of anxiety levels by age, sex, economic need, and age at onset. The use of a different instrument may be indicated for future studies.

We introduce a novel system for recognition of partially occluded and rotated images. The system is based on a hierarchical network of integrate-and-fire spiking neurons with random synaptic connections and a novel organization process. The network generates integrated output sequences that are used for image classification. The network performed satisfactorily given appropriate topology, i.e. the number of neurons and synaptic connections, which corresponded to the size of input images. Comparison of Synaptic Plasticity Activity Rule (SAPR) and Spike Timing Dependant Plasticity (STDP) rules, used to update connections between the neurons, indicated that the SAPR gave better results and thus was used throughout. Test results showed that the network performed better than Support Vector Machines. We also introduced a stopping criterion based on entropy, which significantly shortened the iterative process while only slightly affecting classification performance.

Youth traumatized by natural disasters report high levels of posttraumatic stress as well as other types of impairing emotional distress symptoms (e.g., anxiety and depression) for many years post-trauma. Implementing school based screening and treatment programs for these youth eliminates barriers to traditional treatment settings and may provide symptom relief. The current study examines the feasibility of conducting school-based trauma-focused treatment program in the wake of disaster. Idiographic evaluation of the treatment process is incorporated into the treatment evaluation through use of multiple baseline design. Youth reporting at least severe levels of posttraumatic stress on the PTSD-RI were recruited for an expanded assessment and treatment (youth ages 8-13; N=6). Treatment (i.e., the StArT program) consisted of 10-weekly individual sessions during which different cognitive behavioral components were introduced. Youth were assessed at pre-treatment, weekly during treatment, and at post-treatment. Quantitative and qualitative findings relative to youth responses to intervention are presented and discussed in terms of the feasibility of conducting treatment in school settings and in terms of individual difference factors contributing to treatment responses. Findings from this study suggest the feasibility of school based interventions through the aid of school counselors and integration of treatment sessions into the school schedule. Youth responses to the intervention were very positive, point toward the efficacy of a disaster trauma focused cognitive behavioral therapy (the StArT program), and help to highlight particularly useful modules in youth.

Entre os objetivos da engenharia geotécnica está a busca pelo entendimento e previsão do comportamento mecânico dos solos. Para isso, existem basicamente duas abordagens: ensaios de laboratório ou ensaios de campo. Em cada obra o Engenheiro Geotécnico deve julgar quais são os métodos e procedimentos mais indicados de investigação, que resultarão em parâmetros confiáveis de projeto. Os ensaios de campo foram desenvolvidos baseados nos solos argilosos e arenosos em virtude dos comportamentos distintamente bem definidos, especialmente em termos de drenagem. O mesmo ocorre para o ensaio DMT, cuja execução e interpretação são influenciadas pelo tipo de solo e pelas condições de drenagem. O grande desafio, neste caso, está na interpretação dos ensaios em solos cuja solicitação ocorre sob condição de drenagem parcial, como nos casos de barragens de rejeito de mineração, ou em depósitos naturais de solos siltosos, onde esta condição pode levar a erros de interpretação. No DMT, a ocorrência de drenagem parcial influencia tanto na etapa de cravação da lâmina, quanto na etapa de expansão da membrana. Neste sentido, o foco deste trabalho está no problema da dissipação de poropressão durante a expansão da membrana, apresentando procedimentos especiais para realização do ensaio DMT. Serão apresentados dois métodos de interpretação de resultados, visando compensar os erros de interpretação causados pela dissipação parcial de poropressão: Método de Dissipação Completa e, Método de Dissipação Incompleta. Este trabalho foi desenvolvido baseado na realização de ensaios de campo, com uma campanha executada em solo brasileiro argiloso, que serviu de base à interpretação, sendo complementada por 6 ensaios realizados em diferentes sítios na Itália. Os resultados dos ensaios realizados pelo Método de Dissipação Completa foram interpretados através de duas abordagens: Método da Igualdade (analítico) e Método Simplificado. Enquanto a interpretação do Método de Dissipação Incompleta é permitida apenas através de procedimento simplificado. A análise paramétrica apresentou comportamentos similares entre ambas abordagens, demonstrando que a taxa de dissipação é o fator que mais influencia nos resultados. Ao final, os métodos foram aplicados e validados em diferentes locais, apresentando resultados adequados e compatíveis com o comportamento previamente definido através de outros ensaios. / Among the geotechnical engineering goals are the understanding and prediction of soil behavior. For this, there are basically two approaches: laboratory or in situ tests. In this case, the Geotechnical Engineer must judge the most appropriate investigation methods and procedures that will result in reliable design parameters. In situ tests were developed for clay and sand given to the fact that the behavior of these soils is well-defined and drainage conditions are properly controlled. The DMT is no exception, with test and interpretation methods influenced by the drainage conditions. The challenge resides in the interpretation of tests carried out in soils under partial-drainage conditions, such as tailings dams or natural deposits of silty soils, where partial-drainage conditions are taking place around the DMT blade leading to errors on its interpretation. The partial drainage condition influences both the DMT blade penetration phase and the membrane expansion phase. In this sense, this work focus on the problem of the pore pressure dissipation taking place simultaneously to membrane expansion. A non-standard procedure is proposed to sounding the DMT in silts that include two methods for DMT interpretation in order to compensate the errors caused by the partial pore pressure dissipation: Method of Complete Dissipation Curve and Method of Incomplete Dissipation Curve. This work was developed based on tests carried out in Brazilian clay soils to develop the proposed approach that was validated latter in non-standard tests carried out in different Italian sites. The results of the tests performed by the complete dissipation method were interpreted through two approaches: Equality Method (analytical) and Simplified Method, while the interpretation of the incomplete dissipation method is possible only through simplified procedure. The parametric analysis showed that these approaches yield similar results, demonstrating that the dissipation rate is the most important factor in the analysis. At the end, the methods were applied and validated at different sites, showing results that are compatible to previously defined behavior of the soils.