Exploring the role of fire, succession, climate, and weather on landscape dynamics using comparative modelling

An assessment of the relative importance of vegetation change and disturbance as agents of landscape change under current and future climates would (1) provide insight into the controls of landscape dynamics, (2) help inform the design and development o

Variable bit rate video time-series and scene modeling using discrete-time statistically self-similar systems

This thesis investigates the application of discrete-time statistically self-similar (DTSS) systems to modeling of variable bit rate (VBR) video traffic data. The work is motivated by the fact that while VBR video has been characterized as self-similar by various researchers, models based on self-similarity considerations have not been previously studied. Given the relationship between self-similarity and long-range dependence the potential for using DTSS model in applications involving modeling of VBR MPEG video traffic data is presented. This thesis initially explores the characteristic properties of the model and then establishes relationships between the discrete-time self-similar model and fractional order transfer function systems. Using white noise as the input, the modeling approach is presented using least-square fitting technique of the output autocorrelations to the correlations of various VBR video trace sequences. This measure is used to compare the model performance with the performance of other existing models such as Markovian, long-range dependent and M/G/(infinity) . The study shows that using heavy-tailed inputs the output of these models can be used to match both the scene time-series correlations as well as scene density functions. Furthermore, the discrete-time self-similar model is applied to scene classification in VBR MPEG video to provide a demonstration of potential application of discrete-time self-similar models in modeling self-similar and long-range dependent data. Simulation results have shown that the proposed modeling technique is indeed a better approach than several earlier approaches and finds application is areas such as automatic scene classification, estimation of motion intensity and metadata generation for MPEG-7 applications

Complementaridade como um gerador de valor em Processos de adopção de business intelligence & analytics

Objective: Investments in Business Intelligence and Analytics (BI&A) are increasingly essential to a firm’s competitiveness. Drawing on the Resource-Based View (RBV), our objective is to analyze the implementation of a BI&A system at the Brazilian National Bank of Economic and Social Development (BNDES) to assess the generation of business value for the organization. Methodology: We collected qualitative data through interviews, participant observation, and internal documents and communications. For data analysis, we followed the general coding, aggregation and synthesis process with the use of the qualitative data analysis software Atlas.ti. Originality: Traditional Information Technology (IT) investment evaluation frameworks, especially on BI&A systems, neglect the dynamic nature and the mutual influences of Information Systems assets and capabilities. Also, these frameworks lack studies on complementary socio-organizational capabilities in the business value generation process. Furthermore, RBV has rarely been employed in the study of the impact of BI&A in organizations. Main results: Our results revealed the critical role played by IT and organizational resources and capacities in the BI&A adoption process, as well as the importance of the dynamics of complementarity and its positive outcomes in business. Theoretical contribution: In our research, we provide evidence of RBV’s potential to elucidate the complexities regarding the generation of sustainable business value, and therefore to explain the distinct results obtained by organizations that adopt BI&A technologies. Objetivo: Las inversiones en Business Intelligence and Analytics (BI&A) son cada vez más esenciales para la competitividad de las empresas. Apoyado en la Visión Basada en Recursos (VBR), este estudio analizó la implementación de un sistema de BI & A en el Banco Nacional de Desarrollo Económico y Social (BNDES) para evaluar la generación de valor para la organización. Método: Datos cualitativos fueron recolectados por medio de entrevistas, observación participante y en documentos internos y comunicaciones. El análisis de los datos siguió el proceso usual de codificación, agregación y síntesis, con ayuda del Atlas.ti, un software de análisis de datos cualitativos. Originalidad: Los enfoques tradicionales de evaluación de inversiones en tecnología de la información (TI), especialmente en el caso de sistemas de BI&A, descuidan la naturaleza dinámica y las influencias mutuas de los activos y las capacidades de TI y las capacidades socio-organizacionales complementarias, en el proceso de generación de valor para el negocio. Además, la Visión Basada en Recursos ha sido poco empleada en el estudio del impacto de sistemas de BI&A en las organizaciones. Resultados: Los resultados del estudio revelaron el papel fundamental desempeñado por los recursos y capacidades organizativas y de TI en el proceso de adopción de BI&A, así como la importancia de la dinámica de complementariedad y sus resultados positivos. Contribuciones teóricas: La investigación proporciona evidencia del potencial de VBR para dilucidar las complejidades involucradas en el uso de TI para la generación de valor para el negocio sostenible, y por lo tanto para explicar los diferentes resultados obtenidos por organizaciones que adopta sistemas de BI&A. Palabras clave: Business Intelligence; Gestión de Tecnología de la Información; Visión basada en recursos; Valor de TI; Recursos complementarios.Objetivo: Os investimentos em Business Intelligence and Analytics (BI&A) são cada vez mais essenciais para a competitividade das empresas. Apoiado na Visão Baseada em Recursos (VBR), este estudo analisou a implementação de um sistema de BI&A no Banco Nacional de Desenvolvimento Econômico e Social (BNDES) para avaliar a geração de valor para a organização. Método: Coletamos dados qualitativos por meio de entrevistas, observação participante e em documentos internos e comunicações.  A análise dos dados seguiu o processo usual de codificação, agregação e síntese, com auxílio do Atlas.ti, um software de análise de dados qualitativos. Originalidade: As abordagens tradicionais de avaliação de investimentos em Tecnologia da Informação (TI), especialmente no caso de sistemas de BI&A, negligenciam a natureza dinâmica e as influências mútuas dos ativos e capacidades de TI e as capacidades sócio-organizacionais complementares, no processo de geração de valor para o negócio. Além disso, a Visão Baseada em Recursos tem sido pouco empregada no estudo do impacto de sistemas de BI&A nas organizações. Resultados: Os resultados do estudo revelaram o papel fundamental desempenhado pelos recursos e capacidades organizacionais e de TI no processo de adoção de BI&A, bem como a importância da dinâmica de complementaridade e seus resultados positivos. Contribuições teóricas: Nesta pesquisa, fornecemos evidências do potencial da VBR para elucidar as complexidades envolvidas no uso da TI para a geração de valor para o negócio sustentável, e, portanto, para explicar os diferentes resultados obtidos por organizações que adotam sistemas de BI&A. Palavras-chave: Business Intelligence; Gestão de Tecnologia da Informação; Visão Baseada em Recursos; Valor de TI; Recursos Complementares

Comparison of Explosion Methods for Large-Scale Unconfined Elongated Explosions with Propane and Methane mixtures

PresentationExisting methods for flame propagation and deflagration to detonation transition (DDT) prediction can be divided into three main categories: empirical models, phenomenological and Computational Fluid Dynamics (CFD) based. The former relies on correlations derived from experimental tests and are usually very simple and fast to apply. Phenomenological methods are simplified models which represent the major physical processes in the explosion. CFD-based models, on the other hand, are more sophisticated and require a high degree of expertise for its usage and data analysis. Although all three types of methods are extremely useful for overpressure and flame speed prediction in scenarios involving accidental industrial explosions, they usually fail to predict the occurrence of deflagration-to-detonation transition (DDT) and flame acceleration for low and medium reactivity fuels, such as propane and methane, in elongated clouds. This can be related to the fact that detonation onset or highly turbulent flames are often ignored for such types of fuel. Having that in mind, this paper aims to conduct a review of current explosion models and compare them to recent large-scale tests with premixed propane-air and methane-air mixtures. The ultimate goal is to identify main flame parameters to be included in explosion analysis and propose modifications to improve overpressure and flame speed prediction for elongated vapor clouds

Budbreak induction in kiwifruit vines cultivated in an organic system by the biological method of single node cutting.

Kiwifruit vines are an alternative approach to diversify Brazilian fruit farming because of the low supply and increase in the demand for their fruits. Hydrogenated cyanamide, which is the most common rest-breaking agent, is highly toxic and its use is not allowed in organic production systems. This study aimed at evaluating the efficiency of alternative rest-breaking agents in kiwifruit vines by using the biological method of single node cutting. Twigs of the cultivar Bruno were collected in an organic orchard in Pelotas, a city located in Rio Grande do Sul state, Brazil. Seven-centimeter-long cuts with a single shoot at the ends were segmented. Cuttings were placed on plastic trays with phenolic foam and soaked in water, at 85% relative humidity on average, and kept in bio-oxygen demand (BOD) incubators at 25± 1 °C and a 16-h photoperiod. Budbreak was evaluated in 2-day and 3-day intervals. The experiment was conducted in a completely randomized design with ten treatments and three replications of ten sampling units each. The following variables were analyzed: average budbreak time (ABT), final budbreak rate (FBR), vigorous budbreak rate (VBR), velocity of budbreak (VB), percentage of open buds (POB) and dormancy index (DI). The rest-breaking agent garlic extract (GE) 10% + mineral oil (MO) 2% was the most efficient one in budbreak induction in both production cycles. Thus, this dose is recommended for budbreak induction in kiwifruit vines grown in an organic system

An Algorithm for Integrated Subsystem Embodiment and System Synthesis

Consider the statement,'A system has two coupled subsystems, one of which dominates the design process. Each subsystem consists of discrete and continuous variables, and is solved using sequential analysis and solution.' To address this type of statement in the design of complex systems, three steps are required, namely, the embodiment of the statement in terms of entities on a computer, the mathematical formulation of subsystem models, and the resulting solution and system synthesis. In complex system decomposition, the subsystems are not isolated, self-supporting entities. Information such as constraints, goals, and design variables may be shared between entities. But many times in engineering problems, full communication and cooperation does not exist, information is incomplete, or one subsystem may dominate the design. Additionally, these engineering problems give rise to mathematical models involving nonlinear functions of both discrete and continuous design variables. In this dissertation an algorithm is developed to handle these types of scenarios for the domain-independent integration of subsystem embodiment, coordination, and system synthesis using constructs from Decision-Based Design, Game Theory, and Multidisciplinary Design Optimization. Implementation of the concept in this dissertation involves testing of the hypotheses using example problems and a motivating case study involving the design of a subsonic passenger aircraft