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1
Neofytou, Giannis. "Mathematical models of RNA interference in plants." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/67207/.
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RNA interference (RNAi), or Post-Transcriptional Gene Silencing (PTGS), is a biological process which uses small RNAs to regulate gene expression on a cellular level, typically by causing the destruction of specfic mRNA molecules. This biological pathway is found in both plants and animals, and can be used as an effective strategy in defending cells against parasitic nucleotide sequences, viruses and transposons. In the case of plants, it also constitutes a major component of the adaptive immune system. RNAi is characterised by the ability to induce sequence-specific degradation of target messenger RNA (mRNAs) and methylation of target gene sequences. The small interfering RNA produced within the initiated cell is not only used locally but can also be transported into neighbouring cells, thus acting as a mobile warning signal. In the first part of the thesis I develop and analyse a new mathematical model of the plant immune response to a viral infection, with particular emphasis on the role of RNA interference. The model explicitly includes two different time delays, one to represent the maturation period of undifferentiated cells, and another to account for the time required for the RNAi propagating signal to reach other parts of the plant, resulting in either recovery or warning of susceptible cells. Analytical and numerical bifurcation theory is used to identify parameter regions associated with recovery and resistant plant phenotypes, as well as possible chronic infections. The analysis shows that the maturation time plays an important role in determining the dynamics, and that long-term host recovery does not depend on the speed of the warning signal but rather on the strength of local recovery. At best, the warning signal can amplify and hasten recovery, but by itself it is not competent at eradicating the infection. In the second part of the thesis I derive and analyse a new mathematical model of plant viral co-infection with particular account for RNA-mediated cross-protection in a single plant host. The model exhibits four non-trivial steady states, i.e. a disease-free steady state, two one-virus endemic equilibria, and a co-infected steady state. I obtained the basic reproduction number for each of the two viral strains and performed extensive numerical bifurcation analysis to investigate the stability of all steady states and identified parameter regions where the system exhibits synergistic or antagonistic interactions between viral strains, as well as different types of host recovery. The results indicate that the propagating component of RNA interference plays a significant role in determining whether both viruses can persist simultaneously, and as such, it controls whether the plant is able to support some constant level of both infections. If the two viruses are sufficiently immunologically related, the least harmful of the two viruses becomes dominant, and the plant experiences cross-protection. In the third part of the thesis I investigate the properties of intracellular dynamics of RNA interference and its capacity as a gene regulator by extending a well known model of RNA interference with time delays. For each of the two amplification pathways of the model, I consider the cumulative effects of delay in dsRNA-primed synthesis associated with the non-instantaneous nature of chemical signals and component transportation delay. An extensive bifurcation analysis is performed to demonstrate the significance of different parameters, and to investigate how time delays can affect the bi-stable regime in the model.
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Sharma, Suraj [Verfasser]. "Mathematical models of glucosinolate metabolism in plants / Suraj Sharma." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2018. http://d-nb.info/1161182772/34.
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Scott, Ryan. "Characterizing Tilt Effects on Wind Plants." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/5035.
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Tilting the nacelle of a wind turbine modifies entrainment into the wind plant and impacts total efficiency. Extreme angles can produce flying and crashing wakes where the wake either disrupts entertainment from the undisturbed flow above or is decimated on the ground. The effect of tilt angle on downstream wake behavior was investigated in a series of wind tunnel experiments. Scale model turbines with a hub height and diameter of 12 cm were arranged in a Cartesian array comprised of four rows of three turbines each. Nacelle tilt was varied in the third row from -15° to 15° in chosen 5° increments. Stereo PIV measurements of the instantaneous velocity field were recorded at four locations for each angle. Tilted wakes are described in terms of the average streamwise velocity field, wall-normal velocity field, Reynolds stresses, and mean vertical transport of kinetic energy. Conditional sampling is used to quantify the importance of sweep vs. ejection events and thus downwards vs. upwards momentum transfer. Additionally, wake center displacement and changes in net power are presented and compared to existing models. The results demonstrate large variations in wake velocity and vertical displacement with enhanced vertical energy and momentum transfer for negative tilt angles. Simulation models accurately predict wake deflection while analytic models deviate considerably highlighting the difficulties in describing tilt phenomena. Negative angles successfully produce crashing wakes and improve the availability of kinetic energy thereby improving the power output of the wind plant.
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Adams, William Mark 1961. "APPLICATION OF THE VARIANCE-TO-MEAN RATIO METHOD FOR DETERMINING NEUTRON MULTIPLICATION PARAMETERS OF CRITICAL AND SUBCRITICAL REACTORS (REACTOR NOISE, FEYNMAN-ALPHA)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275438.
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Matuszyńska, Anna [Verfasser]. "Mathematical models of light acclimation mechanisms in higher plants and green algae / Anna Matuszyńska." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2016. http://d-nb.info/112174561X/34.
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Virillo, Carolina Bernucci. "Dinamica e estrutura de populações de especies lenhosas no cerrado de Itirapina, SP." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315015.
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Orientador: Flavio Antonio Maes dos SantosDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Foi estudada a estrutura de tamanho de Xylopia aromatica, Roupala montana, Miconia albicans, Dalbergia miscolobium e Myrcia lingua em três áreas de 0,5 ha (V1, V2 e V3) em um fragmento de cerrado localizado dentro da Estação Ecológica e Experimental de Itirapina (22º 15¿ S; 47º 49¿ W), no município de Itirapina, SP. A espécie que apresentou maior número de indivíduos amostrados (7522) no total das áreas foi X. aromatica, e a que apresentou o menor número (536) foi D. miscolobium. O número de indivíduos de cada espécie variou entre as áreas, e R. montana ocorreu em apenas uma delas (V1). A área com maior abundância de cada uma das espécies não foi coincidente: R. montana, M. albicans e M. lingua ocorreram em maior abundância em V1, enquanto X. aromatica e D. miscolobium ocorreram em maior abundância em V2. A estrutura de tamanho pareceu relacionada à abundância, sendo que as populações com maior abundância apresentaram estruturas de tamanho em formato de ¿Jinvertido¿, sugerindo que as diferenças entre as áreas estão ligadas à maior ou menor presença de indivíduos pequenos. Para cada espécie, as estruturas de tamanho observadas diferiram entre as três áreas, indicando a importância de se realizar estudos demográficos em diferentes áreas e abrangendo diferentes escalas, já que mesmo considerando áreas próximas dentro de um mesmo fragmento foram encontradas diferenças nas estruturas populacionais
Abstract: Not informed
Mestrado
Mestre em Biologia Vegetal
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Ndakidemi, Patrick Alois. "Nutritional characterisation of the rhizosphere of symbiotic cowpea and maize plants in different cropping system." Thesis, Cape Peninsula University of Technology, 2005. http://hdl.handle.net/20.500.11838/762.
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Thesis (DTech (Chemistry))--Cape Peninsula University of Technology, 2005A 2-factorial experiment, involving 3 levels of phosphorus (0, 40, and 80 kg P.ha-I ) as main treatment and 4 cropping systems (mono crop, maize/cowpea inter-row, maize/cowpea intra-row, and maize/cowpea intra-hole cropping) as sub-treatment was conducted in the field for 2 consecutive years in 2003 and 2004 to assess i) the effects of exogenous P supply and cropping system on the concentrations of plant-available nutrients in the rhizosphere of cowpea and maize; ii) the effect of exogenous P supply on tissue concentrations of minerals in nodulated cowpea and maize in mixed plant cultures iii) the effects of exogenous P supply and cropping system on plant growth and N2 fixation, and iv) the effects of exogenous P supply and cropping system on phosphatase activity and microbial biomass in the rhizosphere of cowpea and maize. At harvest, it was found that applying 40 or 80 kg P.ha-I significantly increased cowpea grain yields by 59-65% in 2003 and 44-55% in 2004. With maize, the increases in grain yield were 2037% in 2003 and 48-55% in 2004 relative to zero-P control. In both cropping seasons, the number of pod-bearing peduncles per plant, the number of pods per plant, the number of seeds per pod, and seed yield per cowpea plant were significantly increased with the application of exogenous P. In contrast, these parameters were all significantly depressed by mixed culture relative to mono crop cowpea. Intercropping maize with cowpea produced higher total yields per unit land area than the sole crop counterpart.
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Rees, C. S. "Mathematical models in an integrated steel making plant." Thesis, University of Hull, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383736.
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Gonzalez, Robert. "Optimal design, scheduling and operation of pipeless batch chemical plants." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/11102.
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Du, Plessis Sydney Charles. "Investigation of process parameters and development of a mathematical model for the purposes of control design and implementation for a wastewater treatment process." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1194.
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Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009The problem for effective and optimal control of wastewater treabnent plants is very important recently because of the increased requirements to the qualitY of the effluent The activated sludge process is a type of wastewater process characterized with complex dynamics and because of this proper control design and implementation strategies are necessary and important for its operation. Since the early seventies, when a major leap forward was made by the widespread introduction of dissolved oxygen control, little progress has been made. The most critical phase in the solution of any control problem is the modelling stage. The primary building block of any modem control exercise is to construct and identify a model for the system to be controlled. The existing full Activated Sludge Model 1 (ASM1) and especially University of Cape Town (UCT) models of the biological processes in the activated sludge process, called in the thesis biological models, are highly complex because they are characterised with a lot of variables that are difficult to be measured on-line, complex dependencies and nonlinear interconnections between the biological variables, many kinetic parameters that are difficult to be determined, . different time scales for the process dynamics. The project considers reduction of the impact of the complexity of the process model over the methods for control design and proposes a solution to the above difficulties by development of a reduced model with small number of variables, but still with the same characteristics as the original full model for the purposes of real time.
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Dvorak, Gary John. "Economic analysis of irrigation pumping plants." Thesis, Kansas State University, 1985. http://hdl.handle.net/2097/9834.
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Zhang, Xu-Sheng. "Mathematical models of plant disease epidemics that involve virus interactions." Thesis, University of Greenwich, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327341.
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Bhatnagar, Rohit. "A model for multi-plant coordination : implications for production planning." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28421.
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Firms in several discrete parts manufacturing industries, e.g., electronics equipment, computers, telecommunications equipment etc. operate in a multi-plant environment where products are processed successively at several plants. Prior studies have ignored the interaction between different plants in a multi-plant scenario. The objective of this dissertation is to study the impact of coordination on the cost performance of a two-plant firm.We propose a model that jointly determines production and inventory decisions so that the total cost of holding inventory and overtime, at the two plants is minimized. Our model captures the interaction between the two plants and is preferable to the uncoordinated or the sequential approach which ignores this interaction. We consider the case with limited capacity and explicitly model setup times. Strategies based on Lagrangian relaxation and Lagrangian decomposition methodologies are proposed to solve the model.
Two main findings emerge from this research. First, our results indicate that coordination could lead to improved cost performance and enhanced profits for firms. Two parameters, the setup time to processing time ratio and the capacity utilization at the two plants played a significant role in determining the cost improvements. Managerial implications relating to implementation of the coordinated model are discussed. The second important finding of this research is that Lagrangian decomposition consistently outperforms Lagrangian relaxation in terms of achieving better deviation from the optimal solution, for this problem. A Linear Programming based technique for further enhancing the convergence between the upper and lower bounds is presented.
In the quest for improved performance, multi-plant coordination represents an important strategy for firms. The contribution of the current research is in modelling some of the salient issues of this problem and exploring promising methodological directions.
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Keenan, David Wayne 1955. "BLOCK PLAN CONSTRUCTION FROM A DELTAHEDRON-BASED ADJACENCY GRAPH." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/292025.
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Ly, Cuong. "Reliability study of the Callide power station electrical system." Thesis, Queensland University of Technology, 1997. https://eprints.qut.edu.au/36023/1/36023_Ly_1997.pdf.
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The reliable operation of the electrical system at Callide Power Station is of extreme importance to the
normal everyday running of the Station.
The electrical system configuration and hardware are inherently very reliable. However, in all cases the
failure of components such as circuit breakers, switchboards, and transformers would directly or indirectly
effect the Station's capability to generate at full load capacity and hence maximise revenue.
This study has applied the principles of reliability and has utilised a reliability software package to do an
analysis on the electrical system at Callide Power Station.
The study analyses other possible system configurations that could increase the reliability of the Station.
The study identifies priority maintenance on load points displaying high reliability indices. An analysis
was done on the impact of unusual system configurations such as Boiler Feed Pump motor startups.
Using the results from the study an appropriate level of maintenance was suggested for the current
Callide electrical system configuration and recommendations on the replacement of some 41 SV circuit
breaker tripping toggles was made.
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JORGENSEN, EDWARD JOHN. "SPECIFICATION ERRORS IN ESTIMATING COST FUNCTIONS: THE CASE OF THE NUCLEAR ELECTRIC GENERATING INDUSTRY." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184149.
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This study is an application of production-cost duality theory. Duality theory is reviewed for the competitive and rate-of-return regulated firm. The cost function is developed for the nuclear electric power generating industry of the United States using capital, fuel and labor factor inputs. A comparison is made between the Generalized Box-Cox (GBC) and Fourier Flexible (FF) functional forms. The GBC functional form nests the Generalized Leontief, Generalized Square Root Quadratic and Translog functional forms, and is based upon a second-order Taylor-series expansion. The FF form follows from a Fourier-series expansion in sine and cosine terms using the Sobolev norm as the goodness of fit measure. The Sobolev norm takes into account first and second derivatives. The cost function and two factor shares are estimated as a system of equations using maximum likehood techniques, with Additive Standard Normal and Logistic Normal error distributions. In summary, none of the special cases of the GBC function form are accepted. Homotheticity of the underlying production technology can be rejected for both the GBC and FF forms, leaving only the unrestricted versions supported by the data. Residual analysis indicates a slight improvement in skewness and kurtosis for univariate and multivariate cases when the Logistic Normal distribution is used.
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Huang, Aiping, and 黃愛平. "An investigation of coastal fumigation effects on nuclear accident consequences in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31213133.
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Cazier, Jean-Baptiste. "Mathematical modelling of gas exchanges in film-wrapped cucumbers /." Alnarp : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5763-7.pdf.
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Sharifnia, Hamidreza. "Safety related model and studies of Trojan Nuclear Power Plant electrical distribution system." PDXScholar, 1988. https://pdxscholar.library.pdx.edu/open_access_etds/3875.
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The most important requirement for running a nuclear power plant safely is having a reliable safety system, especially during the emergency shutdown condition. For performing a scrutiny load flow and voltage drop study a detailed and comprehensive electrical model for the emergency electrical distribution system of the Trojan Nuclear Power Plant has been developed. This model includes the representation of the transformers, circuit breakers, motors, cables and load data from 4160 volts level down to the individual 480 volts loads.
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Camara, C. D. J. "Plant identification using model reference techniques." Thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/23544.
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Janse, Van Vuuren Adriaan. "Niche Occupation in Biological Species Competition." Thesis, Stellenbosch : University of Stellenbosch, 2008. http://hdl.handle.net/10019.1/2932.
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Thesis (MSc (Logistics))--University of Stellenbosch, 2008.The primary question considered in this study is whether a small population of a biological species introduced into a resource-heterogeneous environment, where it competes for these resources with an already established native species, will be able to invade successfully. A two-component autonomous system of reaction-diffusion equations with spatially inhomogeneous Lotka-Volterra competitive reaction terms and diffusion coefficients is derived as the governing equations of the competitive scenario. The model parameters for which the introduced species is able to invade describe the realized niche of that species. A linear stability analysis is performed for the model in the case where the resource heterogeneity is represented by, and the diffusion coefficients are, two-toned functions. In the case where the native species is not directly affected by the resource heterogeneity, necessary and sufficient conditions for successful invasion are derived. In the case where the native species is directly affected by the resource heterogeneity only sufficient conditions for successful invasion are derived. The reaction-diffusion equations employed in the model are deterministic. However, in reality biological species are subject to stochastic population perturbations. It is argued that the ability of the invading species to recover from a population perturbation is correlated with the persistence of the species in the niche that it occupies. Hence, invasion time is used as a relative measure to quantify the rate at which a species’ population distribution recovers from perturbation. Moreover, finite difference and spectral difference methods are employed to solve the model scenarios numerically and to corroborate the results of the linear stability analysis. Finally, a case study is performed. The model is instantiated with parameters that represent two different cultivars of barley in a hypothetical environment characterized by spatially varying water availability and the sufficient conditions for successful invasion are verified for this hypothetical scenario.
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Trinkle, Joachim. "Analysis of power ground planes." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0005.
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[Truncated introduction] A major contribution of this thesis is the observation that the N port impedance parameters for the distribution planes can be modelled as simple LC series elements in the frequency range over which the interesting interactions between the loading elements and the planes occur. Loosely speaking, the C represents the inter-plane capacitance and the L is associated with a first order frequency trend of the transfer and input impedances associated with the planes. In the literature, values for L have been obtained for power ground plane structures using curve fitting techniques [38]. In this thesis, formulae are developed for L based on the modal summation expression. As for the impedance case, the approach developed in the thesis that removes the singular behaviour, results in computational efficient expressions. Preliminary results on the simple LC model were presented by the author in [42, 43] The results reported in the thesis extend this work in the light of the new impedance model proposed. The simple LC characterisation enables the development of new low frequency expression for the input and transfer impedance for ports on planes loaded with many decoupling capacitors. The expressions are based on a one off frequency independent decomposition of the inductance matrix associated with the placement of the capacitors. The eigen-mode decomposition eliminates the need for matrix inversion at each frequency point and leads to an efficient computational procedure for calculating the impedance of loaded planes. Furthermore, the interaction between the capacitors and planes is clearly seen in the analytical expressions. This has led to new insights regarding the interaction of multiple capacitors with supply planes in terms of location, resonance mechanisms, pole locations and damping. These insights are beneficial to the understanding and optimisation of printed circuit board power distribution systems.
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Rosado, Linares Jesús. "Analysis of some diffusive and kinetic models in mathematical biology and physics." Doctoral thesis, Universitat Autònoma de Barcelona, 2010. http://hdl.handle.net/10803/3113.
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Almeida, Sheila Souza de. "Otimização de layout de plantas quimicas utilizando o problema de designação quadratica." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267187.
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Orientador: Reginaldo GuirardelloDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: O Layout de uma indústria é de grande preocupação no seu desenvolvimento e, por este motivo, engenheiros e pesquisadores vêm cada vez mais se aprofundando no assunto. A escolha de um bom Layout tem influência nos custos, na segurança, operação e manutenção que são fatores de grande importância para o projeto de planta industrial. Este trabalho tem como objetivo o desenvolvimento da metodologia através de um modelo matemático de otimização para a definição de um Layout industrial através da minimização da função custo, tendo como restrições os critérios de espaço para a segurança, operação e manutenção da planta. Será utilizado como modelo de otimização o problema de atribuição quadrático (QAP), onde se alocam os elementos em uma malha de posições predeterminadas, minimizando a função objetivo. Como este modelo tem uma grande dificuldade em encontrar soluções exatas em tempo viável para a otimização de problemas com grande número de elementos, será utilizado como alternativa métodos heurísticos, que são métodos que encontram soluções rápidas em tempo curto, encontrando uma aproximação para a solução ótima, de fácil implementação e pouco espaço de memória. Dentre as técnicas heurísticas encontra-se o algoritmo Simulated Annealing, um método no qual a solução ótima pode não ser obtida, mas soluções muito próximas a ela são geradas em um tempo de execução muito menor que outras técnicas. Uma característica típica do algoritmo de Simulated Annealing é que além de aceitar soluções que representam melhoramentos no custo, também aceita "deteriorações" (soluções com custo maior) com um certo limite. O mecanismo de geração de soluções escolhido neste trabalho foi a troca de posições entre pares de elementos. A planta escolhida para este estudo foi a de produção de poliéster com 50 equipamentos. Foi necessário estimar com precisão o tamanho e a geometria da rede, para que o tempo computacional fosse o melhor para cada caso. Os resultados indicam que o método escolhido mostrou-se adequado e os Layouts obtidos foram satisfatórios.
Abstract: The layout of an industry is of great concern to its development, and for this particular reason, engineers and researchers are increasingly diving deeper into the subject. Choosing a good layout has a direct influence on costs, security, operations and maintenance, which are all factors of large importance for the project of an industrial plant. This study aims at the development of the methodology through a mathematical optimization model for the definition of an industrial layout by minimizing the cost function, with the restrictions of space criteria for safety, operation and maintenance of the plant. The quadratic assignment problem (QAP), which allocates the elements on to a mesh of preset positions thus minimizing the objective function, will be used as an optimization model. Layout problems usually have great difficulty to encounter exact solutions in viable time for the optimization of problems containing a large numbers of elements; therefore, the alternative heuristic method will be used. This method encounters rapid solutions in short timeframes, finding an approximation for an optimal solution, easy to implement and requires a small amount of storage space. Among the heuristic techniques is the Simulated Annealing algorithm, a method in which an optimal solution may not be obtained, however solutions very close to it are generated in an execution time much smaller than other techniques. A typical characteristic of the Simulated Annealing algorithm is that in addition to accepting solutions that represent improvements in cost, it also accepts deterioration (solutions with greater costs) within a certain limit. The mechanism of generation of new solutions chosen in this study was to change positions between the pairs of elements. In order to demonstrate the proposed approach, a polyester production plant with 50 pieces of equipment was chosen. It was necessary to estimate with precision the size and geometry of the network, so that the computational time was the best for each case. The results indicate that the chosen method proved to be appropriate and the layouts obtained were satisfactory.
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
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Liu, Jiping. "Modelling inter- and intra-specific competition effects in loblolly pine (Pinus taeda L.) plantations." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/39707.
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Accounting for competition effects is an essential step in building any stand growth simulator. However, accurate modelling of competition effects depends upon a clear understanding of quantitative relationships of various aspects of stand dynamics, including distributional parameters and spatial statistics. This study addressed four aspects of competition effects: 1) competition effects on distributional parameter dynamics of tree size variables; 2) inter-specific (loblolly pine vs. hardwood) and intra-specific competition effects on basal area growth, 3) dynamics of spatial statistical characteristics of DBH and total height, and their relevance to intertree competition, 4) and spatial properties of competition measures by available stand simulators for loblolly pine (Pinus taeda L.) plantations. Competition was found to affect the distribution parameters such as coefficient of variation, skewness, and the general shapes of distributions for diameter measurements, total height, crown width and crown height. Competition expedites size differentiation and thereby increases distribution variability for all variables except crown height. Intertree competition also drives skewness of these variables negative, although the distributions of crown heights tends to be more symmetric. Normality assumption generally holds for diameter measurement, but distributions of total height and crown width deviate from, and those of crown height approach, normality with intensified competition. A set of competition driven equations was developed for the distribution parameters and was validated. The differences of distribution parameters among the variables studied could be attributed to their biological meanings.Ph. D.
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Wallens, Sabine A. J. G. "Modélisation des émissions de composés volatils par la végétation." Doctoral thesis, Universite Libre de Bruxelles, 2004. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/241310.
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Teixeira, Filho Aristoteles de Jesus. "Fluxos de agua em especie de citro (citrus sinensis L. Osbeck - laranja pera) - Campinas - São Paulo." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257231.
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Orientador: Jose Teixeira FilhoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
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Resumo: As variáveis ecofisiológicas exercem grande influência, não somente no comportamento vegetativo das plantas cultivadas, mas, sobretudo no seu desempenho em relação às características produtivas. Os estudos sobre trocas gasosas têm-se ampliado desde a década de oitenta, dada a sua importância em cultivos tropicais, tal qual, em variedades de citros. Tem-se investigado que os estômatos são o principal ponto de controle do fluxo de água, sendo o déficit de pressão hídrica do ar apontada como a força motora para a transpiração, e a quantidade de água no solo é o fator decisivo para o abastecimento hídrico da planta. Dessa forma, a eficiência do uso da água pela cultura pode ser considerada como uma relação custo-benefício para o aumento da produção dos citros, com o mínimo impacto na reserva hídrica do ecossistema, haja vista que no Brasil, apesar da incidência de períodos de déficits hídricos temporários em várias regiões citrícolas, predomina o cultivo sem irrigação. O Brasil é um dos maiores produtores mundiais de frutas cítricas, destacando-se os Estados: Bahia, Minas Gerais, Rio Grande do Sul, Rio de Janeiro, São Paulo e Sergipe. Com plantios acima de 1.100.000 hectares, os citros têm grande importância comercial no Brasil, sendo São Paulo o maior produtor com aproximadamente 70% da produção nacional. O retorno econômico proveniente deste produto é de grande importância para o crescimento do setor agrícola do país. A partir da safra de 1979-1981, a citricultura brasileira vem ocupando o primeiro lugar em produção dentro da América do Sul. Para tal, o estudo foi conduzido no campo experimental da Faculdade de Engenharia Agrícola (FEAGRI) da Universidade Estadual de Campinas, localizado no município de Campinas, entre as coordenadas geográficas de 22o53¿20¿ de Latitude sul e o meridiano 47o04¿40¿ de Longitude oeste de Greenwich. O experimento foi conduzido em cinco plantas de citros de mesma variedade (Citrus sinensis L. Osbeck), realizando medidas de transpiração, condutância estomática, radiação fotossinteticamente ativa, radiação incidente total e déficit de pressão de vapor saturado. No período considerado observou-se que a maior média diária da transpiração 4,63 mmol.m-2.s-1 na PL4T2 e a menor foi de 1,53 mmol.m-2.s-1 na PL1EVP1. O melhor modelo foi aquele que considerou que resposta da transpiração foliar estar diretamente associado ao déficit de pressão de vapor saturado
Abstract: The variables ecofisiológicas exercise great influence, not only in the vegetative behavior of the cultivated plants, but, above all in your acting in relation to the productive characteristics. The studies on gas exchange have been enlarging since the decade of eighty, given your importance in tropical cultivations, just as, in citrus varieties. Has been investigating that the stomatal is the principal point of control of the flow of water, being the deficit of pressure water of the air appeared as the motive force for the perspiration, and the amount of water in the soil it is the decisive factor for the provisioning water of the plant. In that way, the efficiency of the use of the water for the culture can be considered as a relationship cost-benefit for the increase of the production of the citrus, with the minimum impact in the reservation water of the ecosystem, have seen that in Brazil, in spite of the incidence of periods of deficits temporary waters in several areas citrícolas, the cultivation prevails without irrigation. Brazil is one of the largest world producers of citric fruits, standing out States: Bahia, Minas Gerais, Rio Grande do Sul, Rio de Janeiro, São Paulo and Sergipe. With plantings above 1.100.000 hectares, the citrus have great commercial importance in Brazil, being São Paulo the largest producing with approximately 70% of the national production. The originating from economical return this product is of great importance for the growth of the agricultural section of the country. Starting from the crop of 1979-1981, the Brazilian citricultura is occupying the first place inside in production of South America. For such, the study was lead in the experimental field of the College of Engenharia Agrícola (FEAGRI) of the State University of Campinas, located in the city of Campinas, enters the geographic coordinates of 22o53¿20¿ of south Latitude and the meridian 47o04¿40¿ of Longitude west of Greenwich. The experiment was led in five plants of citrus of same variety (Citrus sinensis L. Osbeck), accomplishing perspiration measures, conductance stomatal, radiation fotossinteticamente activates, total incident radiation and deficit of pressure of saturated vapor. In the considered period it was observed that the largest average daily rate of the perspiration 4.63 mmol.m-2.s-1 in PL4T2 and the smallest was of 1.53 mmol.m-2.s-1 in PL1EVP1. The best model was that that considered that answer of the perspiration to foliate to be directly associated to the deficit of pressure of saturated vapor
Doutorado
Agua e Solo
Doutor em Engenharia Agrícola
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Oliveira, Jhone Gleison de. "Avaliação de modelos matemáticos de cinética de degradação ruminal." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/2431.
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CAPESO trabalho foi realizado para identificar os modelos com melhor ajuste aos perfis de degradação de forrageiras utilizadas na alimentação de ruminantes com o intuito de obter estimativas mais verossímeis dos parâmetros que descrevem a cinética de degradação ruminal. Foram realizados três ensaios, comparando quatro modelos matemáticos (M1, M2, M3 e M4) de cinética de degradação. No ensaio 1, foram utilizadas dez forrageiras, entre elas, três gramíneas de clima temperado, quatro gramíneas de clima tropical e três leguminosas de clima temperado, todas analisadas em triplicatas (30 perfis). Nos ensaios 2 e 3 foi avaliada a aveia IAPAR 126, submetida a quatro níveis de adubação nitrogenada (12 perfis) e quatro intervalos entre cortes respectivamente (12 perfis). Além dos testes de modelagem, foram realizadas análises bromatológicas para obter possíveis correlações com as estimativas dos parâmetros que descrevem a cinética de degradação. A qualidade de ajuste dos modelos aos dados foi verificada por meio do critério de Akaike corrigido (AICcr), da diferença entre os valores de AICcr (Δr), da probabilidade de verossimilhança (Wr) e da verossimilhança relativa (ERr). O M3 obteve melhor ajuste a 72% dos perfis, o M1 a 22% e o M4 a 6%. Houve correlação positiva entre EE e LDA, EE e PB e entre LDA e PB no ensaio 3 e correlação negativa entre k2 e aFDN, k2 e k1 e entre PB e k1. No ensaio 2 houve correlação positiva entre k1 e k2 e correlação negativa entre PB e k1. O M3 reproduziu estimativas de parâmetros mais verossímeis para forrageiras com maior teor de fibra e menores teores de carboidratos não fibrosos e de proteína. O modelo M1 possui melhor qualidade de ajuste a perfis de produção de gás de forrageiras com maiores teores de carboidratos não fibrosos e baixo conteúdo de lignina.
The aim of this study was to identify the models which best fit the degradation profiles of some forages used in ruminant nutrition in order to obtain better estimates of the parameters that describe the kinetics of ruminal degradation. It were taken Three trials comparing four mathematical model (M1, M2, M3 and M4) degradation kinetics with different forages. In assay 1 ten forages were used, including three temperate grasses, four tropical grasses and three temperate legumes, all analyzed in triplicate (30 profiles). In assay 2 and 3 was evaluated oat IAPAR 126, subjected to four levels of nitrogen fertilization (12 profiles) harvest at four differents time (12 profiles). In addition to the modeling testing, chemical analysis were taken for possible correlations with the estimates of the parameters describing the kinetics of degradation. The way of the model fit to the data was verified by the corrected Akaike criterion (AICcr) the difference between the AICcr values (Δr), the probability of likelihood (Wr) and the relative likelihood (ERr). The M3 was the best fit to 72% of the profiles, the M1 to 22% and the M4 to 6%. There was a positive correlation between EE and LDA, EE and PB and between LDA and PB in the assay 3 and negative correlation between k2 and aFDN, k2 and k1 and between PB and k1. In trial 2 there was a positive correlation between k1 and k2 and negative correlation between PB and k1. The M3 results in estimates more credible parameters for forage with higher fiber and lower levels of non-fibrous carbohydrates and protein. The M1 has better quality forage adjust the gas production profiles with higher carbohydrate content not fibrous and lower lignin contente.
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Rajagopalan, Jayendar. "Symbolic and connectionist machine learning techniques for short-term electric load forecasting." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08222009-040506/.
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Uong, Hoang. "The application of the ordered list method and the dynamic programming to the unit commitment." PDXScholar, 1989. https://pdxscholar.library.pdx.edu/open_access_etds/3948.
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Palmer, Kurt D. "Data collection plans and meta models for chemical process flowsheet simulators." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/24511.
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Franklin, Oskar. "Plant and forest dynamics in response to nitrogen availability /." Uppsala : Swedish University of Agricultural Sciences, 2003. http://diss-epsilon.slu.se/archive/00000345/.
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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003.Appendix consists of reprints of three papers and a manuscript, three of which are co-authored with others. Includes bibliographical references. Also partially issued electronically via World Wide Web in PDF format; online version lacks appendix.
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Johnson, Sean Robert. "Development and application of spectral databases and mathematical models in the study of plant natural products biosynthesis." Thesis, Washington State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10164019.
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Plant natural products are useful for many different applications, including medicines, flavors and fragrances, and industrial uses. Two important aspects of plant natural products research are the identification of compounds in their source plants, and the characterization of the processes involved in their biosynthesis. To aid in the identification of plant natural products, we developed the Spektraris family of databases. These databases include highperformance liquid chromatography mass spectrometry data, and 13C and 1H nuclear magnetic resonance data, which are searchable through an online interface. The utility of Spektraris was validated by using it to identify compounds in plant extracts and as part of a workflow to elucidate the structure of a previously undescribed compound.
Mints have a long history of use as model systems for studying the processes of terpene natural products biosynthesis in specialized plant tissues. The mint family (Lamiaceae), synthesizes and stores volatile terpenes in glandular trichomes. Using a comparative transcriptomic approach, we identified differences in gene expression of monoterpene biosynthetic genes among mint species with different oil profiles. We also assembled the genome of a mint species, Mentha longifolia. The genome assembly will be valuable for future mint research.
To further investigate biosynthetic processes in mint, I developed a detailed mathematical model of the metabolism of peppermint glandular trichomes. The model incorporates multiple sources of data, including transcriptome data, metabolite data, enzymatic data from the peppermint literature, and previously developed models of plant metabolism. The creation of a new metabolic modeling software package, called YASMEnv, facilitated construction of the model. Model-based simulated reaction knockouts using flux balance analysis revealed that fermentation may be important for ATP regeneration in secretory phase glandular trichomes. Follow up experiments confirmed high levels of alcohol dehydrogenase activity in secretory phase isolated trichomes. Simulations also supported an essential role for ferredoxin and ferredoxin-NADP reductase. Transcriptome analysis revealed the presence of an isoform of ferredoxin in trichomes distinct from the one expressed in root. The presence of a distinct ferredoxin isoform in trichomes supports the hypothesis that selection pressure for efficient natural products biosynthesis may also act on the enzymes of primary metabolism.
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Ibrahim, Razi. "Predicting Potato Yield Loss Due to Metribuzin Sensitivity in North Dakota." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/28860.
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A linear-log model to predict yield loss due to metribuzin injury was established by Love et. al. in 1993. Two experiments were conducted in 2016 and 2017 to evaluate and improve this model for application in North Dakota (ND). Metribuzin was applied (1.12 a.i./ha) when potato plants were 20-30 cm tall at Inkster, ND. The model did not accurately predict yield loss in 2016 but performed better in 2017. Foliar injury was more correlated with yield reduction than relative plant height. Results also indicated that new models that used foliar injury at 21 days after treatment (DAT) data and at 7 DAT data, most accurately predicted total yield loss and marketable yield loss, respectively. The new model performed similar to the previous model, but unlike previous model it can predict yield loss very early in growing season (21 DAT).USDA Specialty Block Grant Program
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Sutherland, Elaine Kennedy. "The effect of prescribed burning on southwestern ponderosa pine growth." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184954.
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Study objectives included determining whether prescribed burning affected ponderosa pine growth; mathematically modeling the growth response to burning; and determining whether forest management history affected growth response. I sampled 188 trees from two areas near Flagstaff, Arizona; one area (Brannigan Flat) had been logged and thinned, and the other (Chimney Spring) had not; both were burned in 1976. Within each study area, control and burned plots were of similar age, vigor, height, and competition index. Trees at Chimney Spring were older, less vigorous, and taller, and had a higher competition index than at Brannigan. For each tree, periodic basal area increment (PBAI) was calculated for the years 1974-1984. To determine which variable would best model growth, postfire PBAI (individual years, 1977-1984) was correlated with previous growth (average PBAI 1974-1976); crown ratio; competition index; thinning index; and diameter. Two models of growth response were developed; one oriented toward satisfying theoretical and research goals, and the other, toward management applications. Growth was modeled using stepwise multiple linear regression, and the dependent variable was postfire PBAI. Research Model independent variables were previous growth, years (climate), and treatment-year interaction, and 72% of total variance was explained. Fire affected growth significantly and negatively for two years, and then burned trees grew similarly to control trees. Management Model independent variables were crown ratio, competition index, crown ratio, subject tree diameter, year, and treatment, and 52% of total variance was explained. This model, too, indicated a slight negative effect of burning on growth. Management history was not a significant determinant of growth response. Both models validated well; the ratio of observed-to-predicted residual mean square was 1.04 and 0.91 (Research and Management Models, respectively). Thinning index was not significantly related to postfire growth, but a change in carbohydrate allocation from stem wood to crown and root expansion could have resulted in observed burning effects. Management implications include (1) short-term growth decline may result from burning, (2) management history did not affect growth response, and (3) burning impact is greatest in dense stands of small trees.
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Garcia, Axel Garcia y. "Modelos para área foliar, fitomassa e extração de nutrientes na cultura de arroz." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-16092002-140818/.
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O objetivo do trabalho foi propor modelos para estimar índice de área foliar, fitomassa seca e extração de macronutrientes pela cultura de arroz, bem como determinar a época de máxima taxa de extração de N e K. O experimento foi conduzido na várzea do Departamento de Produção Vegetal da ESALQ/USP. O solo foi classificado como Gleissolo Eutrófico, horizonte A chernozênico, textura média a argilosa (FAO Unesco: Gleysols; USDA: Humic Haplaquept). Foi utilizada a variedade cultivada IAC 103, caracterizada por ser de ciclo médio e de alto rendimento. As variáveis observadas foram o índice de área foliar, a fitomassa seca em diferentes compartimentos da planta (raiz, folha e colmo e panícula) e os teores de macronutrientes por unidade de fitomassa seca. Para estimativa da extração de N, P, K, Ca, Mg e S, levou-se em consideração o teor de macronutrientes na planta e a produção, por unidade de área, de fitomassa seca. Em função dos resultados obtidos, foram propostos modelos cuja base matemática é fundamentada em eventos biológicos que acontecem ao longo do ciclo da cultura. Os modelos propostos apresentaram adequado desempenho para definir ordem de grandeza dos valores de índice de área foliar, fitomassa seca, extração de macronutrientes pela cultura de arroz, bem como para estimar a máxima taxa de absorção de N e K.The objective of this study was to propose models to estimate leaf area index, dry matter and uptake macronutrients, and to determinate the maximum N and K uptake rates moment by rice crop. The field experiment was carried out at a wetland area of the Crop Science Department, University of São Paulo, Brazil. The soil is classified as Humic Haplaquept (FAO UNESCO: Gleysols; Brazil: Gleissolo Eutrófico). The rice variety IAC 103 (middle season cycle and high yield) was used. Observed variables were leaf area index, dry matter from different parts of the plant (root, leaf and stem, and panicle) and macronutrient content. To estimate N, P, K, Ca, Mg and S extraction, the macronutrient content and dry matter were used. As results of this study, phytotechnical models, based on biological events that occurred during the crop cycle, were proposed. These models showed a satisfactory behavior to define the magnitude of estimated leaf area index, dry matter, macronutrient extraction by rice crop and maximum N and K uptake rates.
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Rogalsky, Dennis Wayne. "Quantifying plant model parameter effects on controller performance /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/9843.
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Kosiba, Andrea. "Effects of irradiation and temperature on shoot growth and development in Blue holly (Ilex x meserveae) /." SLU Alnarp : Department of Crop Science, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200541.pdf.
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Mathis, Andrew Wiley. "Electromagnetic modeling of interconnects incorporating perforated ground planes." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/14822.
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Paulino, Silvia Elisandra Pasqua. "Modelos agrometeorológicos para estimação do número de frutos por planta em cultivares de laranja doce na região de Limeira-SP." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-17052005-165526/.
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O estabelecimento de modelos que permitam previsões de tendências de produtividade, apontando se as colheitas serão menores ou maiores, é de grande importância para todos os elos da cadeia citrícola. Este trabalho teve por objetivo identificar e avaliar a influência de variáveis agrometeorológicas, em diferentes fases do ciclo da cultura, para propor modelos empíricos para estimação do número de frutos por planta nas variedades cultivadas de laranja doce Pêra, Valência e Hamlin, na região de Limeira-SP. Foram utilizados dados amostrais de número de frutos por planta, em três classes de idade, referentes à estimativa anual de produção da indústria de suco paulista, no total de 15 safras (1990/91 a 2004/05), e dados meteorológicos (temperatura máxima e mínima e precipitação) para o município de Limeira (22º32S, 47º27W, 639 metros). Foram determinados inicialmente os coeficientes de correlação linear entre número de frutos por planta e variáveis agrometeorológicas componentes do balanço hídrico e temperatura, em diferentes períodos. Foram desenvolvidos modelos de regressão linear múltipla, mediante procedimento stepwise, para os subconjuntos de variáveis agrometeorológicas que apresentaram as maiores correlações significativas com o número de frutos por planta em diferentes fases do ciclo da cultura. As condições meteorológicas durante as fases de crescimento vegetativo de verão, pré-florescimento, florescimento e início de crescimento dos frutos, influenciam a produção de frutos por planta. Os modelos obtidos apresentaram ajustes satisfatórios entre valores observados e estimados, com coeficiente de determinação variando de 0,72 a 0,87.The establishment of models that allows forecasting of yield tendencies, pointing if the harvest will be minors or majors, is important for the citrus industry. This work had the purpose of evaluating the influence of meteorological variables in different phases of the crop cycle to propose empirical models to estimate the number of fruits per plant on the cultivated varieties of sweet orange Pêra, 'Valência' and Hamlin, to the region of Limeira-SP, Brazil. Samples of number of fruits per plant have been used, classified in three age classes, related to the annual juice production estimative from citrus industry of the State of São Paulo, on the total of 15 harvests (1990/91 to 2004/05), and meteorological data of maximum and minimum air temperature and precipitation of Limeira-SP (22º32'S, 47º27'W, 639 meters), Brazil. The correlation coefficients among number of fruits per plant and meteorological variables components of the water balance and air temperature in different periods were initially computed. The linear multiple regression models were developed using 'stepwise' procedure, for all variables that presented the major significant correlations with the number of fruits per plant in different phases of the crop cycle. The meteorological conditions during the phases of vegetative growth of summer, pre-flowering, flowering and beginning of fruits growth influenced the fruits per plant production. The proposed models presented satisfactory adjustments among observed and estimated values, with determination coefficients from 0.72 to 0.87.
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Lin, TsungPo. "An adaptive modeling and simulation environment for combined-cycle data reconciliation and degradation estimation." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24819.
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Thesis (Ph.D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.Committee Chair: Dimitri Mavris; Committee Member: Erwing Calleros; Committee Member: Hongmei Chen; Committee Member: Mark Waters; Committee Member: Vitali Volovoi.
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Kaspi, Yohai. "Turbulent convection in the anelastic rotating sphere : a model for the circulation on the giant planets." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45780.
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Thesis (Ph. D.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2008.Includes bibliographical references (p. 207-221).
This thesis studies the dynamics of a rotating compressible gas sphere, driven by internal convection, as a model for the dynamics on the giant planets. We develop a new general circulation model for the Jovian atmosphere, based on the MITgcm dynamical core augmenting the nonhydrostatic model. The grid extends deep into the planet's interior allowing the model to compute the dynamics of a whole sphere of gas rather than a spherical shell (including the strong variations in gravity and the equation of state). Different from most previous 3D convection models, this model is anelastic rather than Boussinesq and thereby incorporates the full density variation of the planet. We show that the density gradients caused by convection drive the system away from an isentropic and therefore barotropic state as previously assumed, leading to significant baroclinic shear. This shear is concentrated mainly in the upper levels and associated with baroclinic compressibility effects. The interior flow organizes in large cyclonically rotating columnar eddies parallel to the rotation axis, which drive upgradient angular momentum eddy fluxes, generating the observed equatorial superrotation. Heat fluxes align with the axis of rotation, contributing to the observed flat meridional emission. We show the transition from weak convection cases with symmetric spiraling columnar modes similar to those found in previous analytic linear theory, to more turbulent cases which exhibit similar, though less regular and solely cyclonic, convection columns which manifest on the surface in the form of waves embedded within the superrotation. We develop a mechanical understanding of this system and scaling laws by studying simpler configurations and the dependence on physical properties such as the rotation period, bottom boundary location and forcing structure. These columnar cyclonic structures propagate eastward, driven by dynamics similar to that of a Rossby wave except that the restoring planetary vorticity gradient is in the opposite direction, due to the spherical geometry in the interior.
(cont.) We further study these interior dynamics using a simplified barotropic annulus model, which shows that the planetary vorticity radial variation causes the eddy angular momentum flux divergence, which drives the superrotating equatorial flow. In addition we study the interaction of the interior dynamics with a stable exterior weather layer, using a quasigeostrophic two layer channel model on a beta plane, where the columnar interior is therefore represented by a negative beta effect. We find that baroclinic instability of even a weak shear can drive strong, stable multiple zonal jets. For this model we find an analytic nonlinear solution, truncated to one growing mode, that exhibits a multiple jet meridional structure, driven by the nonlinear interaction between the eddies. Finally, given the density field from our 3D convection model we derive the high order gravitational spectra of Jupiter, which is a measurable quantity for the upcoming JUNO mission to Jupiter.
by Yohai Kaspi.
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PARLETTE, EDWARD BRUCE. "GENERALIZED FUNCTION SOLUTIONS TO THE FOKKER-PLANCK EQUATION." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187933.
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In problems involving highly forward-peaked scattering, the Boltzmann transport equation can be simplified using the Fokker-Planck model. The purpose of this project was to develop an analytical solution to the resulting Fokker-Planck equation. This analytical solution can then be used to benchmark numerical transport codes. A numerical solution to the Fokker-Planck equation was also developed. The analytical solution found is a generalized function. It satisfies the purpose of the project with two limitations. The first limitation is that the solution can only be evaluated for certain sources. The second limitation is that the solution can only be evaluated for small times. The moments of the Fokker-Planck equation can be evaluated for any time. The numerical solution developed works for all sources and all times. The analytical solution, then, provides an accurate and precise benchmark under certain conditions. The numerical solution provides a less accurate benchmark under all conditions.
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Bester, Margarete Joan. "Design of an automated decision support system for scheduling tasks in a generalized job-shop." Thesis, Stellenbosch : Stellenbosch University, 2006. http://hdl.handle.net/10019.1/21734.
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Macedo, Elisa Patricio. "Modelagem matemática como ferramenta para elaboração de planos de ação emergencial." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-24032014-101411/.
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O tema segurança de barragens vem adquirindo destaque no cenário brasileiro. Isso se deu tendo em vista os acidentes ocorridos e a recente lei n° 12.334, aprovada em setembro de 2010, que estabeleceu normas e padrões. Desta maneira, os empreendedores voltaram sua atenção para esse tema, resultando em uma grande demanda de ferramentas que possibilitem a adequação de suas barragens à legislação. Esse estudo, então, tem como objetivo apresentar e avaliar um sistema de composição de modelos matemáticos que podem ser utilizados na elaboração dos Planos de Ação Emergencial (PAE). O estudo apresenta uma breve revisão sobre o tema segurança de barragens, identificando quais produtos devem ser buscados por meio da utilização dos modelos. Quanto à composição de modelos, tem-se, inicialmente, o modelo de previsão de precipitação que fornece os dados para o modelo hidrológico sendo que este, por sua vez, fornece dados para o hidrodinâmico. Neste último estão incluídos também o modelo de formação da brecha e o cálculo de routing dos reservatórios. Com os resultados de nível dágua, as manchas de inundação são traçadas com o auxílio dos modelos digitais de terreno (MDT). Os aplicativos utilizados em cada modelo foram o ETA no modelo de previsão de precipitação, SMAP como modelo hidrológico e o CLiv+ como modelo hidrodinâmico. O MDT utilizado foi o gerado por meio das curvas de nível do IBGE e pontos levantados no local. Assim, esses modelos foram utilizados para simulações das barragens dos rios Pardo e Mogi Guaçu, sendo elas a UHE Caconde, a UHE Euclides da Cunha, a UHE Limoeiro e a PCH Mogi Guaçu. Desta forma foi realizada a calibração destes modelos e a simulação de vazões acima da de restrição e de cenários de rompimento. Esses resultados foram gerados para um estudo realizado pela Fundação Centro Tecnológico de Hidráulica para a AES Tietê denominado Sistema de Gerenciamento de Ações Emergenciais (SGAE). Assim, para validação do sistema de composição de modelos e para verificação de pontos de melhoria, foram realizadas avaliações do sistema. Essas foram a comparação dos dados de previsão de precipitação com dados observados, comparação entre diferentes MDTs e comparação entre os aplicativos CLiv+ e o HEC-RAS.Recent dam failures and also the approval of Law n° 12.334, establishing rules and standards to be followed in dam safety management, made dam safety area gain prominence in the Brazilian scenario in the last years. Dams owners focused their attention into this theme increasing the demand for tools in order to adequate theirs dam documentation to the requirements of the law. This study presents and evaluate an ensemble of mathematical models that can be used in scenarios analysis that are usually considered in Emergency Action Plans EAP elaboration. The study includes a review about dam safety regulation and a group of models that can be applied for impact evaluation, establishing data and information needed. Models considered include the forecast precipitation model, that provides data to the hydrological model which, in its turn, provides the information for the hydraulic model. This latter also include the dam breaching model and the reservoir routing calculation model. The flooded area maps are obtained using the results of water level and digital elevation model. This arrange of models apply the ETA as the forecast precipitation model, the SMAP model as the hydrologic model and Cliv+ as the hydraulic model. The digital terrain model used was created by using the cartographic base from IBGE and a point elevation survey in the study area. These models were utilized in simulations involving dams located at the Pardo and Mogi Guaçu Rivers, in Sao Paulo State, named UHE Caconde, UHE Euclides da Cunha, UHE Limoeiro and PCH Mogi Guaçu. Models were calibrated under observed flow conditions and prospective simulations were done considering different scenarios like design hydrographs and failure, under a research project developed by Fundação Centro Tecnológico de Hidráulica and AES Tietê. To validate the system and identify improvement points, a comparison of forecasted precipitation and water levels were carried out considering observed data, different DTMs and hydraulic models (CLIV + and HEC-RAS).
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Ballard, Todd Curtis. "Mathematical Models of Zea mays: Grain Yield and Aboveground Biomass Applied to Ear Flex and within Row Spacing Variability." TopSCHOLAR®, 2008. http://digitalcommons.wku.edu/theses/41.
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Field studies were conducted during the summers of 2007 and 2008 at the Agricultural Research and Education Complex, Western Kentucky University, Warren County, KY and commercial production fields in Caldwell County, KY, Warrick County IN, and Vanderburgh County, IN. The goals of these studies were to further validate the Duncan grain yield model, the Russell aboveground biomass model, and to study the effect of inconsistent spacing within rows on Zea mays L. yield. Plant spacing other than uniform decreases grain yield and profitability. The population experiments conducted at the Warren County location were a randomized complete block design with three planting densities, three varieties (c.v. DeKalb DKC6547, DeKalb DKC6346, DeKalb DKC6478) in 2007 and (DeKalb DKC6478, DeKalb DKC6342, and DeKalb DKC6544) in 2008, and three replications. Seeds were planted in rows 76 cm apart and 9.1 m long with four rows per plot in a no-till system on a Crider Silt Loam with pH of 6.8 and 1.5% organic matter. The effect of variable within row spacing was evaluated in commercial production fields by randomly selecting five adjacent rows of 5.3 meters in length at each location. Grain yield for each row was then curve fitted both linearly and exponentially.
Minimizing interspecies competition was essential to evaluating the effects of competition within Zea mays L. A burn-down application of 2,4-D and glyphosate was used prior to planting. The most common weeds in the plots were Sorghum halepense L. (johnsongrass), Trifolium repens L. (white clover), and Taraxacum officinale L. (common dandelion) . Glyphosate was reapplied throughout the growing season due to reemergence of S. halepense and Ipomoea hederacea Jacq. (ivyleaf morningglory).
The weight of each ear was recorded and one row from each plot was randomly selected to shell. The moisture content was measured from a subsample twice each row using an electrical conductivity moisture meter. The mean of the two moisture readings was used as the moisture content from the plot. Cob weights from shelled ears were recorded to determine the grain/cob mass ratio. This ratio was used to project the grain weight for the remaining harvested rows.
Duncan’s grain yield model and Russell’s biomass model were curve fitted to the data for areas of 0.00040 hectares at the p < 0.05 significance level or greater in all population density plots. Individual plant grain masses were curve fitted to Duncan’s model with p < 0.05 significance in 3 out of 15 plots. Grain mass was negatively correlated (R < 0) with standard deviation of within row spacing in 14 of 15 plots. A linear fit to this trend was significant in only 2 of 15 plots. The Duncan yield curve and the Russell aboveground biomass model fit all 6 genotype by environment interactions for 2007 and 2008 to the α = 0.05 level of confidence when evaluated over a 5.3 meter length on 76.2 cm wide rows. Individual plants fit linearly at α = 0.05 in 9 out of 15 plots. Individual plants fit the Duncan yield curve at α = 0.05 in 4 out of 15 plots.
Standard deviation of within row spacing fit grain yield loss significantly at &#; = 0.05 in two of 15 plots. The individual plant spacing and local population density collectively fit nine plots significantly at α = 0.05 or better.
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Santos, Dayana Lardo dos. "Zoneamento da favorabilidade climática para a ocorrência da ferrugem alaranjada da cana-de-açúcar nas principais regiões produtoras do Brasil e da Austrália." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-21082013-104149/.
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O Brasil, maior expoente do setor sucroalcooleiro mundial, apresenta como um dos entraves para obter elevadas produtividades a ocorrência de doenças fúngicas, as quais limitam o potencial produtivo do canavial. Atualmente, um dos grandes desafios para a comunidade canavieira é a recém-introduzida ferrugem alaranjada, doença causada pelo fungo Puccinia kuehnii, a qual foi detectada pela primeira vez no Brasil na safra 2009/10, ano em que as chuvas excederam os valores normais e as temperaturas foram amenas. Dada a grande dependência que as doenças fúngicas têm das condições climáticas para se manifestarem, o presente estudo teve por objetivo avaliar as condições meteorológicas que foram observadas durante as epidemias de ferrugem alaranjada ocorridas na província de Queensland, Austrália, em 1999/2000, e no estado de São Paulo, em 2009/2010, e a partir dessas elaborar modelos que possibilitassem estimar a severidade da doença, de modo a se estabelecer o zoneamento da favorabilidade climática para sua ocorrência. Com base nessas informações foram elaborados mapas de favorabilidade climática para a ocorrência da ferrugem no estado de São Paulo e na província de Queensland. As variáveis climáticas favoráveis à ocorrência da ferrugem alaranjada foram o número de decêndios com excedente hídrico (NDEXC) e o número de decêndios com temperatura média ideal para a infecção (NDTideal). Essas variáveis foram utilizadas no desenvolvimento de modelos lineares para determinação da severidade da doença, com base nos dados observados em diferentes regiões do estado de São Paulo. A elaboração do Índice de Favorabilidade Climática à Ferrugem Alaranjada da Cana-de-açúcar (IFAC) se baseou numa ponderação das severidades estimadas para séries de 15 a 30 anos. Posteriormente, o IFAC foi correlacionado com as coordenadas geográficas e a altitude o que permitiu se estimar o IFAC para todo o Estado de São Paulo. Esse modelo também foi aplicado para a Província de Queensland, Austrália. O IFAC foi empregado na confecção de mapas nos quais se estabeleceram os zoneamentos das regiões de favorabilidade climática à doença. Observou-se que as regiões canavieiras no oeste paulista apresentam risco muito baixo a moderado, enquanto que nas regiões no centro-leste do Estado, o risco é moderado-alto a alto seguindo uma tendência longitudinal. Para Queensland, a região mais favorável à doença é na faixa leste da província, exatamente nas regiões onde se concentra a produção de cana-de-açúcar.Brazil, the largest exponent of the sugarcane sector in the world, presents as one of the obstacles for obtaining high yields the occurrence of diseases, which limits the potential productivity of the crop. Presently, one the greatest challenge for sugarcane production is newly introduced sugarcane disease, named orange rust, caused by Puccinia kuehni, which was detected by the first time in Brazil during 2009-2010 growing season, when the rainfall exceed the normal values and temperatures remained mild. Considering the great influence of climate conditions on plant diseases occurrence, the present study aimed to evaluate the weather conditions that prevailed during the sugarcane orange rust epidemic in province of Queensland, Australia, in 1999-2000 growing season, and in the state of São Paulo, Brazil, in 2009-2010 growing season, and base on that to develop a disease severity model in order to establish the climate favorability zoning for its occurrence. Based on these data, maps of orange rust climatic favorability were elaborated for the state of São Paulo and province of Queensland. The climatic variables favorable for conditioning orange rust were the number of ten-day periods with soil water surplus (NDEXC) and the number of ten-day periods with average temperature within the ideal range for the disease (NDTideal). With these variables, linear models were developed to determine the severity of the disease, based on disease and weather data observed in different regions of the state of São Paulo. The Climatic Favorability Index for Sugarcane Orange Rust Occurrence (IFAC) was based on the weighting of the disease severities estimated for weather series of 15 to 30 years. After that, IFAC was correlated with the geographical coordinates and altitude which allowed estimating it for all the state of São Paulo. This procedure was also applied for the province of Queensland, Australia. The IFAC was used to generate maps for zoning the regions of climatic favorability for the disease. The maps allowed to observe that for the state of São Paulo, the west region presents vary low to moderate risk for the disease, while the center-east region presents moderate-high to high risk. For the province of Queensland, the most favorable region for orange rust occurrence is the east, exactly where the sugarcane production is concentrated.
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Lenane, Ian Joseph. "An investigation of mathematical models for spray droplet spreading on plant leaves with new results applicable to uniform, horizontal, solid surfaces." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/204179/1/Ian_Lenane_Thesis.pdf.
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This thesis presents a literature review of mathematical models developed to simulate the spreading of agrichemical spray droplets impacting on plant leaf surfaces. New results are derived to predict how far droplets will spread when deposited or sprayed perpendicularly onto a dry, uniform, horizontal, solid surface. The first part of the new research provides equations to predict the extent a sessile droplet will spread on these surfaces as well as its itemized energy budget. The second part examines scaling law formulae to predict the maximum spreading factor for droplets impacting the solid at non-zero velocities.
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Tran, Tat Dat. "Information Geometry and the Wright-Fisher model of Mathematical Population Genetics." Doctoral thesis, Universitätsbibliothek Leipzig, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-90508.
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My thesis addresses a systematic approach to stochastic models in population genetics; in particular, the Wright-Fisher models affected only by the random genetic drift. I used various mathematical methods such as Probability, PDE, and Geometry to answer an important question: \"How do genetic change factors (random genetic drift, selection, mutation, migration, random environment, etc.) affect the behavior of gene frequencies or genotype frequencies in generations?”.
In a Hardy-Weinberg model, the Mendelian population model of a very large number of individuals without genetic change factors, the answer is simple by the Hardy-Weinberg principle: gene frequencies remain unchanged from generation to generation, and genotype frequencies from the second generation onward remain also unchanged from generation to generation.
With directional genetic change factors (selection, mutation, migration), we will have a deterministic dynamics of gene frequencies, which has been studied rather in detail. With non-directional genetic change factors (random genetic drift, random environment), we will have a stochastic dynamics of gene frequencies, which has been studied with much more interests. A combination of these factors has also been considered.
We consider a monoecious diploid population of fixed size N with n + 1 possible alleles at a given locus A, and assume that the evolution of population was only affected by the random genetic drift. The question is that what the behavior of the distribution of relative frequencies of alleles in time and its stochastic quantities are.
When N is large enough, we can approximate this discrete Markov chain to a continuous Markov with the same characteristics. In 1931, Kolmogorov first introduced a nice relation between a continuous Markov process and diffusion equations. These equations called the (backward/forward) Kolmogorov equations which have been first applied in population genetics in 1945 by Wright.
Note that these equations are singular parabolic equations (diffusion coefficients vanish on boundary). To solve them, we use generalized hypergeometric functions. To know more about what will happen after the first exit time, or more general, the behavior of whole process, in joint work with J. Hofrichter, we define the global solution by moment conditions; calculate the component solutions by boundary flux method and combinatorics method.
One interesting property is that some statistical quantities of interest are solutions of a singular elliptic second order linear equation with discontinuous (or incomplete) boundary values. A lot of papers, textbooks have used this property to find those quantities. However, the uniqueness of these problems has not been proved. Littler, in his PhD thesis in 1975, took up the uniqueness problem but his proof, in my view, is not rigorous. In joint work with J. Hofrichter, we showed two different ways to prove the uniqueness rigorously. The first way is the approximation method. The second way is the blow-up method which is conducted by J. Hofrichter.
By applying the Information Geometry, which was first introduced by Amari in 1985, we see that the local state space is an Einstein space, and also a dually flat manifold with the Fisher metric; the differential operator of the Kolmogorov equation is the affine Laplacian which can be represented in various coordinates and on various spaces. Dynamics on the whole state space explains some biological phenomena.
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Knecht, Billberger Magnus F. "Plant growth - stoichiometry and competition : theory development in ecosystem ecology /." Uppsala : Dept. of Ecology and Environmental Research, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200624.pdf.
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