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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Modelos de simulação da cultura do milho - uso na determinação das quebras de produtividade (Yield Gaps) e na previsão de safra da cultura no Brasil / Maize simulation models - use to determine yield gaps and yield forecasting in Brazil

Yury Catalani Nepomuceno Duarte 18 January 2018 (has links)
Sendo o cereal mais produzido no mundo e em larga expansão, os sistemas de produção de milho são altamente complexos e sua produção é diretamente dependente de fatores ligados tanto ao clima local quanto ao manejo da cultura. Para auxiliar na determinação tanto dos patamares produtivos de milho quanto quantificar o impacto causado por condições adversas tanto de clima quanto de manejo, pode-se lançar mão do uso de modelos de simulação de culturas. Para que os modelos possam ser devidamente aplicados, uma base solida de dados meteorológicos deve ser consistida, a fim de alimentar esses modelos. Nesse sentido, o presente estudo teve como objetivos: i) avaliar dois sistemas de obtenção de dados meteorológicos, o NASA-POWER e o DailyGridded, comparando-os com dados medidos em estações de solo; ii) calibrar, testar e combinar os modelos de simulação MZA-FAO, CSM DSSAT Ceres-Maize e APSIM-Maize, a fim de estimar as produtividades potenciais e atingíveis do milho no Brasil; iii) avaliar o impacto na produtividade causado pelo posicionamento da semeadura em diferentes tipos de solo; iv) desenvolver e avaliar um sistema de previsão de safra baseado em modelos de simulação; v) mapear as produtividades potencial, atingível e real do milho no Brasil, identificando regiões mais aptas ao cultivo e vi) determinar e mapear as quebras de produtividade, ou yield gaps (YG) da cultura do milho no Brasil. Comparando os dados climáticos dos sistemas em ponto de grade com os dados de estações meteorológicas de superfície, na escala diária, encontrou-se boa correlação entre as variáveis meteorológicas, inclusive para a chuva, com R2 da ordem de 0,58 e índice d = 0,85. O desempenho da combinação dos modelos ao final da calibração e ajuste se mostrou superior ao desempenho dos modelos individuais, com erros absolutos médios relativamente baixos (EAM = 627 kg ha-1) e com boa precisão (R2 = 0,62) e ótima acurácia (d = 1,00). Durante a avaliação da influência das épocas de semeadura e do tipo de solo no patamar produtivo do milho, observou-se que esse varia de acordo com a região estudada e apresenta seus valores máximos e com menores riscos à produção quando a semeaduras coincidem com o início do período de chuvas do local. O sistema de previsão de safra, baseado em modelos de simulação de cultura teve seu melhor desempenho simulando produtividades de milho semeados no início da safra e no final da safrinha, sendo capaz de prever de forma satisfatória a produtividade com até 25 dias antes da colheita. Para o estudo dos YGs, 152 locais foram avaliados e suas produtividades potenciais e atingíveis foram comparadas às produtividades reais, obtidas junto ao IBGE. Os maiores YGs referentes ao déficit hídrico se deram em solos arenosos e durante os meses de outono e inverno, usualmente mais secos na maioria das regiões brasileiras, atingindo valores de quebra superiores a 12000 kg ha-1. Quanto ao YG causado pelo manejo, esse foi maior nas regiões menos tecnificadas, como na região Norte e na Nordeste, apresentando valores superiores a 6000 kg ha-1. Já as regiões mais tecnificadas e tradicionais na produção de milho, como a região Sul e a Centro-Oeste, os YGs referentes ao manejo foram inferiores a 3500 kg ha-1 na maioria dos casos. / Maize is the most important cereal cultivated in the world, being its production system very complex and its productivity directly affected by climatic and crop management factors. In order to quantify the impacts caused by water and crop management deficits on maize yield, the use of crop simulation models is very useful. For properly apply these models, a solid basis of meteorological data is required. In this sense, the present study had as objectives: i) to evaluate two meteorological gridded data, NASA-POWER and DailyGridded, by comparing them with measured data from surface stations; (ii) to calibrate, evaluate and combine the MZA-FAO, CSM DSSAT Ceres-Maize and APSIM-Maize simulation models to estimate the maize potential and attainable yields in Brazil; iii) to evaluate the impact caused by the different sowing dates and soil types on maize yield; iv) to develop and evaluate a crop forecasting system based on crop simulation models and climatological data; v) to map the potential and the attainable maize yields in Brazil, identifying the most suitable regions for cultivation, and vi) to determine and map maize yields and yield gaps (YG) in Brazil. Comparing the gridded climatic data with observed ones, on a daily basis, a good agreement was found for all weather variables, including rainfall, with R2 = 0.58 and d = 0,85. The performances of the combination of the models at the end of the calibration and evaluation phases were better than those obtained with the individual models, with relatively low mean absolute error (EAM = 627 kg ha-1) and with good precision (R2 = 0.62) and accuracy (d = 1.00). During the evaluation of different sowing dates and soil types on maize yield, it was observed that this variable depends on the region and presents the maximum values and, consequently, the minimum risk during the sowings in the beginning of the rainy season of each site. The crop forecasting system, based on crop simulation models, had its best performance for simulating maize yields when the sowings were performed at the beginning of the main season and at the end of the second season, when it was able to predict yield satisfactorily 25 days before harvest. For the YG analysis, 152 sites were assessed and their potential and attainable yields were compared to the actual yields reported by IBGE. The highest YGs caused by water deficit occurred for sandy soils and during the autumn and winter months, usually dry in most of Brazilian regions, reaching values above 12000 kg ha-1. For YG caused by crop management, the values were higher in the less technified regions, such as in the North and Northeast regions, with values above 6000 kg ha-1. In contrast, more traditional maize production regions, such as the South and Center-West, presented YG caused by crop management, lower than 3500 kg ha-1 in most cases.
82

Improving irrigated cropping systems on the high plains using crop simulation models

Pachta, Christopher James January 1900 (has links)
Master of Science / Department of Agronomy / Scott A. Staggenborg / Irrigated cropping systems on the High Plains are dominated by water intensive continuous corn (Zea mays L.) production, which along with other factors has caused a decline in the Ogallala aquifer. Potentially demand for water from the aquifer could be decreased by including drought tolerant crops, like grain sorghum (Sorghum bicolor L.) and cotton (Gossypium hirsutum L.), in the cropping systems. This study calibrated the CERES-Maize, CERES-Sorghum, and CROPGRO-Cotton models for the High Plains and studied the simulated effects of different irrigation amounts and initial soil water contents on corn, cotton, and grain sorghum. Input files for calibration were created from irrigated and dryland research plots across Kansas. Information was collected on: soil physical properties, dry matter, leaf area, initial and final soil water content, management, and weather. CERES-Maize simulated grain yield, kernel number, ear number, and seed weight across the locations with root mean square errors (RMSE) of 2891 kg ha-1, 1283 kernels m-2, 1.6 ears m-2, and 38.02 mg kernel-1, respectively. CERES-Sorghum simulated grain yield, kernel number, head number, and seed weight with RMSEs of 2150 kg ha-1, 5755 kernels m-2, 0.13 heads m-2, and 4.51 mg kernel-1. CROPGRO-Cotton simulated lint yield and boll number with RMSEs of 487 kg ha-1 and 25.97 bolls m-2. Simulations were also conducted with CERES-Maize, CERES-Sorghum, and CROPGRO-Cotton to evaluate the effects of irrigation amounts and initial soil water content on yield, evapotranspiration (ET), water use efficiency (WUE), available soil water at maturity, and gross income per hectare. Simulations used weather data from Garden City, KS from 1961 to 1999. Irrigation amounts were different for all variables for corn and grain sorghum. For cotton, yield, WUE, soil water, and gross income were not different between the top two irrigation amounts. For corn and grain sorghum, initial soil water content was only different at 50% plant available water. Initial soil water had no affect on cotton, except for ET at 50%. Simulations showed that cotton yields are similar at lower irrigation. Also, cropping systems that include cotton have the potential to reduce overall irrigation demand on the Ogallala aquifer, potentially prolonging the life of the aquifer.
83

Predikce produkce popela jako vedlejšího produktu spalování v uhelné elektrárně Ledvice / Prediction of ash production as a side effect of burning coal in the coal power plant Ledvice

Zikmundová, Alena January 2015 (has links)
The topic of this thesis is the prediction of production of ash as a side product in the coal power plant Ledvice. The goal of the first two chapters was to present the development of consumption of electricity and the resources of electric energy in Europe, show the trends in energy industry at the beginning of the 21st century, introduce the energetic company ČEZ, summarize the issue of side products in power plants and present the new block of the coal power plant Ledvice. In the theory section, the methods of linear programming, simulation models, linear regression model and artificial neural networks were presented. These methods were used in the application section to create an optimization model for the processing of the side products of burning coal, to create a simulation of the production of side products and to use the results to optimize the processing of the side products of burning coal and to create a model to predict the production of bottom ash to coal burned ratio based on the characteristics of the coal burned moisture, ash and lower heating value using artificial neural networks.
84

Produção de forragem em Brachiaria brizantha: adaptação, geração e avaliação de modelos empíricos e mecanicistas para estimativa do acúmulo de forragem / Forage production Brachiaria brizantha: adaptation, generation and evaluation of empirical and mechanistic models to estimate the forage accumulation

Pedro Gomes da Cruz 14 December 2010 (has links)
As gramíneas forrageiras representam plantas de grande interesse econômico. Diversas são as espécies tropicais que apresentam-se como opções para a formação de pastagens no Brasil, desta forma objetivou-se neste trabalho a determinação de fatores que devem ser considerados em modelos para a predição da produção de forragem em cultivares de Brachiaria brizantha; gerar e testar modelos empíricos para a predição da taxa de acúmulo de matéria seca no capim-marandu; e parametrizar e comparar modelos mecanicistas, na estimativa de produção de matéria seca do capim-marandu. Para isso, foi conduzido um experimento no campo experimental da Embrapa Pecuária Sudeste, localizada no município de São Carlos SP. O delineamento experimental utilizado foi em blocos completos inteiramente casualizado com quatro repetições. Os cultivares de Brachiaria brizantha cv. Marandu, Xaraés e Piatã foram avaliados em crescimento livre e com freqüência de corte a cada 35 dias, em esquema fatorial 3x2. Foram avaliados: acúmulo de forragem, índice de área foliar (IAF), área foliar específica (AFE), altura do meristema apical, altura de plantas e estádio de desenvolvimento do perfilho. O corte influenciou a massa seca de forragem acumulada por corte acima do resíduo em todos os cultivares de B. brizantha, sendo que o cultivar Xaraés apresentou o maior acúmulo quando comparado aos cultivares Marandu e Piatã. Na avaliação da AFE, houve efeito de cultivar, onde o cultivar Piatã apresentou a menor média (136,3 cm2.g-1), entretanto, os cultivares Marandu e Xaraés foram semelhantes (163,6 e 156,7 cm2.g-1; P>0,05). O corte não influenciou nos valores de AFE, mas a AFE diminuiu ao longo do tempo. No acúmulo de forragem ao longo do ano, destacou-se o cultivar Xaraés quando comparado aos cultivares Marandu e Piatã (25.539 contra 18.148 e 19.292 kg MS.ha-1.ano-1). O IAF acima do resíduo apresentou altas correlações com o acúmulo de forragem ao longo do ano com valores de r de 0,95, 0,93 e 0,94 para os cultivares Marandu, Piatã e Xaraés, respectivamente (P<0,0001). A partição de massa seca da parte aérea foi influenciada pelo corte e pelas variações estacionais de temperatura e luminosidade. Em todos os cultivares foram observados períodos de juvenilidade, sendo um importante fator a ser considerado em modelos envolvendo o crescimento de Brachiaria brizantha. A abordagem de modelos empíricos mostrou-se uma alternativa prática e viável, capaz de estimar a produção de forragem. O modelo que relacionou a variável climática de graus-dias corrigida pela relação ETR/ETP apresentou a melhor predição da taxa média de acúmulo de matéria seca para a cidade de São Carlos. O CROPGRO apresentou subestimativas na produção de matéria seca nos diferentes anos, principalmente no período de primavera/verão, responsável pelas maiores produções. Já o GRAZPLAN simulou satisfatoriamente as produções de massa seca, estimando valores bem próximos aos valores reais de produção, tanto no período de menor produção (outono/inverno) quanto no período de maior produção (primavera/verão). / The grasses represent plants of great economic interest. Several tropical species that are presented as options for pasture establishment in Brazil, so the objective of this work is to determine the factors that should be considered in models for prediction of forage in Brachiaria brizantha generate and test empirical models for predicting the rate of dry matter accumulation in Marandu grass, and parameterize and compare mechanistic models to estimate the dry matter production of Marandu grass. For this, an experiment was conducted at Embrapa Southeast Cattle, located in São Carlos - SP. The experimental design was randomized complete block with four replications. The cultivars of Brachiaria brizantha cv. Marandu, Xaraés and Piatã were valued at free growth and with a cut each 35 days in a factorial 3x2. It was evaluated: herbage accumulation, leaf area index (LAI), at specific leaf area (SLA), height of apical meristem, plant height and tiller growth stage. The cut affected the herbage dry matter accumulated by cutting up the residue in all cultivars of B. brizantha, and the Xaraés cultivar showed the greatest accumulation when compared to the cultivars and Marandu Piatã. In the evaluation of ERA, there was no effect of cultivar, where the Piatã had the lowest average (136,3 cm2.g-1), however Xaraés and Marandu cultivars were similar (163,6 and 156,7cm2.g-1, P> 0.05). The cut did not affect the values of AFE, but the SLA has decreased over time. In herbage accumulation over the years, the highlight was the cultivar Xaraés compared to cultivars Marandu and Piatã (25,539 against 18,148 and 19,292 kg MS.ha-1.year-1). LAI above the residue showed a high correlation with herbage accumulation over the years with r values of 0,95, 0,93 and 0,94 for cultivars Marandu Piata and Xaraés, respectively (P <0,0001) . The partitioning of dry mass of shoots was influenced by the cut and the seasonal variations in temperature and luminosity. In all cultivars were observed periods of juvenility, being an important factor to be considered in models involving the growth of Brachiaria brizantha. The approach of empirical models proved to be a practical and viable alternative, capable of estimating forage production. The model relating the variable climate of degree-days adjusted by the ratio AE/PE showed the best prediction of the rate of accumulation of dry matter to the city of São Carlos. The CROPGRO had underestimated the dry matter production in different years, especially during the spring/summer, responsible for higher yields. Already the GRAZPLAN simulated satisfactorily dry mass production, estimating values very close to the real values of production, both in periods of low production (fall/winter) and in the period of peak production (spring/summer).
85

Grafický editor simulačních modelů / Graphical Editor of Simulation Models

Bulka, Pavol January 2011 (has links)
This thesis deals with development of a graphical editor of simulation models. Design of the editor is based on a research which was carried out among professional simulation systems with graphical user interface. The new graphical editor is based on DEVS formalism since it is quite hard to implement a reliable simulation tool. This formalism was verified in great number of its implementation. One of them is Adevs library which is used in editor. Plugins can be used to provide additional features (i.e. another simulator) without need for changing the code of the editor. Another way to extend editor functionality are user scripts. The thesis presents the software development process of the editor in detail. Furthermore, a brief summary of DEVS formalism along with some DEVS modifications and extensions is included. In the end, a set of tests which were used for editor testing on multiple platforms is added.
86

Automatic Kernel Intercommunication Interface for a Simulation Platform

Latif, Umair 14 August 2017 (has links)
CluSys is a simulation platform that is developed by LuK GmbH & Co. KG to support product development engineers. It integrates different simulation calculation kernels and provides a collaborative environment for tool-independent chain simulation processes. The data between simulation modules in chain simulations is exchanged by defining intercommunications between individual parameters manually. This thesis provides a concept to automate the data exchange process between the parameters of different simulation models based on their physical meaning. Different approaches implemented in contemporary simulation environments are discussed, analyzed and a customized solution compatible with CluSys based on abstract interface approach is developed. This concept is implemented using an SQL database creating a parameter dictionary and an automatic intercommunication interface that uses the dictionary to recognize the parameters and define data exchange processes between them automatically. The implemented solution makes the data exchange between parameters of different simulation models independent of their labels, module names or units.
87

The Calibration And Verification Of Simulation Models For Toll Plazas

Russo, Christopher 01 January 2008 (has links)
A great deal of research has been conducted on Central Florida toll roads to better understand the characteristics of the tolling operation. In this thesis, the development and calibration of a toll plaza simulation models will be analyzed using two simulation programs varying mostly in their modeling theory. The two models utilized are, SHAKER, a deterministic queuing model for vehicles utilizing toll collection facilities, and VISSIM, a globally popular stochastic simulation software. The benefits of simulation models leads to the purpose of this thesis, which is to examine the effectiveness of two toll modeling programs that are similar in purpose but vary in approach and methodology. Both SHAKER and VISSIM toll plaza models have the potential to work as a tool that can estimate the maximum throughput and capacity of toll plazas. Major operational benefits resulting from developing these models are to simulate and evaluate how traffic conditions will change when demand increases, when and if queues increase when a lane is closed due to maintenance or construction, the impact of constructing additional lanes, or determining whether or not the best lane type configuration is currently implemented. To effectively calibrate any model available site data must be used to compare simulation results to for model validity. In an effort to correctly calibrate the SHAKER toll plaza tool and VISSIM model, an extensive field collection procedure was conducted at four Florida Turnpike operated toll facilities located in Central Florida. Each site differed from the others in terms of number of lanes, lane configuration, toll base fee, highway location, traffic demand, and vehicle percentage. The sites chosen for data collection were: the Lake Jesup Mainline Plaza along the Seminole Expressway (SR-417), the Beachline West Expressway Toll Plaza along the SR-528, the Daniel Webster Western Beltway Plaza along SR-429, and the Leesburg Toll Plaza along the Florida Turnpike Mainline SR-91. Upon completion of calibration of the two simulation models it is determined that each of the two software are successful in modeling toll plaza capacity and queuing. As expected, each simulation model does possess benefits over the other in terms of set up time, analysis reporting time, and practicality of results. The SHAKER model setup takes mere seconds in order to create a network and input vehicle, another few seconds to calibrate driving parameters, and roughly 10 additional seconds to report analysis. Conversely, setting up the VISSIM model, even for the most experienced user, can take several hours and the report analysis time can take several more hours as it is dependant on the number of required simulation runs and complexity of the network. VISSIM is most beneficial by the fact that its modeling allows for driver variability while SHAKER assumes equilibrium amongst lane choice and queuing. This creates a more realistic condition to observed traffic patterns. Even though differences are prevalent, it is important that in each simulation model the capacity is accurately simulated and each can be used to benefit operational situations related to toll plaza traffic conditions.
88

Investigation, Analysis, and Modeling of Longwall Face-to-Face Transfers

Patrick, William Charles 09 June 2008 (has links)
This dissertation reports on research efforts to investigate, analyze, and model longwall face-to-face transfers through the use of operations research techniques. The purpose is to reduce overall transfer time and the variation of transfer times among operations within the U. S. longwall industry. The research includes: (1) investigation of existing longwall transfers to determine standard and variant procedures; (2) development of comprehensive activity sequence models of existing longwall transfers; (3) generation of a simulation model for longwall transfers in various geological and mining conditions; and, (4) investigation of the economic feasibility of time-cost tradeoffs in the transfer procedure. Face transfer field data were collected from three eastern U.S. mining operations. From these data, general operational characteristics, transfer personnel utilization, and transfer procedures are described. A comparison of methods provide a breakdown of transfer activities, identify critical activities, and establish the state-of-the-art in transfer technology. Project scheduling models are developed for each operation using precedence networking analytical techniques and are applied through a computerized commercial software package. The project scheduling models accurately represent each of the operations' transfer procedures and provide information on the criticality of transfer activities and estimated project duration. Simulation models are developed, using Monte Carlo techniques, to combine analytical project scheduling with probability-based transfer activity durations. The simulation models closely match the results of the project scheduling models and provide information on the statistical tendencies of critical activities, paths, and project durations. The economic feasibility of reducing transfer time is analytically evaluated by collapsing critical activities and attempting an alternative roof control method. When compared to the lost production potential of longwall mining systems, the two time-cost trade-off procedures are proven, by the transfer simulation model, to be economically viable. This research is expected to contribute to the longwall mining industry by offering an objective approach that can be used in the prediction, planning, preparation, and implementation of longwall face equipment transfers. / Ph. D.
89

Modelos matemáticos para estimar a sazonalidade de produção em pastagens de Panicum maximum cv. Mombaça, em regiões do Estado de São Paulo / Mathematical models to estimate seasonal pastures production of Panicum maximum cv. Mombaça

Araujo, Leandro Coelho de 13 February 2012 (has links)
Um experimento em campo foi implantado na Embrapa Pecuária Sudeste em São Carlos-SP (21°57\'42\"S, 47°50\'28\"W) de 2010 a 20 11. Foram conduzidos simultaneamente dois ensaios com o capim-mombaça que diferenciaram entre si pela presença ou não da irrigação. O delineado em blocos completos casualizados com quatro repetições foi utilizado em cada ensaio. Os tratamentos foram representados pela soma diária da temperatura média do ar de 250; 500; 750 e 1000° C durante cada período de rebrotação. Após as avaliações referentes ao tratamento de 1000 °C acumulados, toda a pastagem era cortada a 0,3 m de altura do solo, fertilizadas (N-P-K) e iniciado um novo ciclo de rebrotação e avaliações. Ao longo de 13 meses foram avaliados 8 ciclos de rebrotação. As variáveis avaliadas em cada tratamento foram acúmulo de massa seca total acima do resíduo, identificação do meristema apical em vegetativo ou reprodutivo, índice hídrico (IH) estimado pela relação entre a evapotranspiração real (ensaio não irrigado) e da cultura (ensaio não irrigado) estimadas tanto pelo método direto (Diviner) e pela evapotranspiração atual com a potencial pelo indireto (Climatológico). Os dados gerados nos experimentos foram utilizados para determinar os valores críticos das principais variáveis que influenciam no crescimento do capim-mombaça, além de parametrizar e avaliar um modelo empírico de graus-dia (GD); um modelo empírico de unidades-fototérmicas (UF); um modelo empírico de índice de crescimento climático (ICC) e um modelo de função biofísica (APSIM-Growth). Os resultados demonstraram que a produção relativa do capimmombaça diminui linearmente com a redução do IH. A temperatura base foi estimada em 15,6 °C e o capim-mombaça, e o período de flores cimento indica que essa cultiva seria uma planta de dias curtos sendo o valor de fotoperíodo crítico próxima a 11,81 h. Os modelos de GD, UF e ICC foram bem ajustados com os dados do experimento irrigado, assim como o modelo APSIM-Growth após a modificação de alguns parâmetros. Durante a etapa de avaliação dos modelos, com dados independentes de pastagem irrigada (literatura) e não irrigada (experimento não irrigado), todos os modelos apresentaram um bom desempenho, sendo o APSIM-Growth o modelo que apresentou um menor erro na média geral (6 kg MS/ha/corte) e o modelo UF o modelo empírico que proporcionou valores preditos mais próximo dos observados, com um erro médio geral de 268 kg MS/ha/corte. / Two experiments were held simultaneously at Embrapa South-East Cattle Research Center (São Carlos, SP, Brazil, 21°57\'42\"S , 47°50\'28\"W) in 2010-2011 using Panicum maximum cv. Mombaça (Guineagrass). They were differentiated by the presence or absence of irrigation. The randomized complete block design with four replications was used. The treatments were determined by cumulative thermal times during each growth cycles (i.e. 250, 500, 750 and 1000 °C, base temperature = 0 °C). After the last sample time (1000° C) of each cycle, all the plots were uniformly cut up to 0.3 m above the soil surface to begin a new cycle of re-growth and sampling. At every new growth cycle the pasture was fertilized (N-P-K). The variables recorded were the dry matter above-residue, identification of apical meristem at vegetative state or flowering one, calculation of water index (WI) by ratio between real evapotranspitarion to crop evapotranspiration using the direct method (Diviner) or actual evapotranspitarion to potential evapotranspitarion usgin an indirect method (Climatologic). The data sets from the experiments were used to determine the critical values of the main variables that may influence the Guineagrass growth, besides parameterizing and evaluating an agroclimatic degree-day model (DDi); a photo-thermal-units model (PUi); a growth climate index model (GCIi) and one biophysical function model (APSIM-Growth). The results showed that the relative production of Guineagrass decreases linearly with the reduction of the WI. The base temperature was estimated equal to 15.6 ° C and Guineagrass is possibly identified as a short-day plant with a photoperiod critical value close to 11.81 h. All models performed well during the parameterization (R2 from 0.78 to 0.86 and coefficient of variation from 27 to 32.1%), and evaluation (R2 from 0.69 to 0.78; agreement index from 0.88 to 0.93; coefficient of variation from 37.6 to 50.2% and mean bias error from 6 to 470 kg DM ha/cutting). APSIM model was the one that showed a minor error and UF model was the empirical model that provided predicted values closer to the observed.
90

Giving emotional contagion ability to virtual agents in Crowds

Fortes Neto, Amyr Borges 09 March 2017 (has links)
Submitted by PPG Ci?ncia da Computa??o (ppgcc@pucrs.br) on 2017-11-13T21:43:46Z No. of bitstreams: 1 AMYR_BORGES_FORTES_NETO_TES.pdf: 2509779 bytes, checksum: 3513c7b9db941d3f24cfdc672eac46f9 (MD5) / Rejected by Caroline Xavier (caroline.xavier@pucrs.br), reason: Devolvido devido ? falta da folha de rosto (p?gina com as principais informa??es) no arquivo PDF, passando direto da capa para a ficha catalogr?fica. on 2017-11-21T12:48:40Z (GMT) / Submitted by PPG Ci?ncia da Computa??o (ppgcc@pucrs.br) on 2017-12-11T16:15:52Z No. of bitstreams: 1 AMYR_BORGES_FORTES_NETO_TES.pdf: 2507882 bytes, checksum: 0ef0935814ab8c8fd102985b55b443f6 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-12-18T13:19:03Z (GMT) No. of bitstreams: 1 AMYR_BORGES_FORTES_NETO_TES.pdf: 2507882 bytes, checksum: 0ef0935814ab8c8fd102985b55b443f6 (MD5) / Made available in DSpace on 2017-12-18T13:24:43Z (GMT). No. of bitstreams: 1 AMYR_BORGES_FORTES_NETO_TES.pdf: 2507882 bytes, checksum: 0ef0935814ab8c8fd102985b55b443f6 (MD5) Previous issue date: 2017-03-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Modelos de simula??o de multid?es t?m tido um papel importante em ci?ncias da computa??o j? h? algumas d?cadas desde os trabalhos pioneiros. No in?cio, agentes simulados em multid?es comportavam-se todos da mesma maneira, e tal comportamento era controlado pelas mesmas regras em todos os agentes. Com o tempo, os modelos de simula??o evoluiram, e come?aram a agregar uma maior variedade de comportamentos nos agentes. Modelos de simula??o de multid?es que implementam diferentes comportamentos nos agentes s?o chamados modelos de Multid?es Heterog?neas, em oposi??o aos modelos de Multid?es Homog?neas precedentes. Modelos de simula??o de multid?es que buscam criar agentes com comportamentos humanos realistas exploram heterogeneidade nos comportamentos dos agentes, na tentativa de atingir tal realismo. Em geral, estudos em psicologia e comportamento humano s?o usados como conhecimento de base, e os comportamentos observados nestes estudos s?o simulados em agentes virtuais. Nesta dire??o, trabalhos recentes em simula??o de multid?es exploram caracter?sticas de personalidade e modelos de emo??es. No campo de emo??es em agentes virtuais, pesquisadores est?o tentando recriar fen?menos de cont?gio de emo??es em pequenos grupos de agentes, ou mesmo estudar o impacto de cont?gio de emo??o entre agentes virtuais e participantes humanos. Sob a cren?a de que cont?gio de emo??o em agentes virtuais possa levar a comportamentos mais realistas em multi?es, este trabalho foca em recriar modelos computacionais de cont?gio de emo??es destinados a pequenos grupos de agentes, adaptando estes modelos para um contexto de simula??o de multid?es. / Crowd simulation models have been playing an important role in computer sciences for a few decades now, since pioneer works. At the beginning, agents simulated on crowds behaved all the same way, such behaviour being controlled by the same set of rules. In time, simulation models evolved and began to incorporate greater variety of behaviours. Crowd simulation models that implement different agent behaviours are so-called Heterogeneous Crowd models, opposing to former Homogeneous Crowd models. Advances in crowd simulation models that attempt to make agents with more realistic human-like behaviours explore heterogeneity of agent behaviours in order to achieve overall simulation realism. In general, human behavioural and psychological studies are used as base of knowledge to simulate observed human behaviours within virtual agents. Toward this direction, later crowd simulation works explore personality traits and emotion models. Some other work in the field of emotional virtual agents, researchers are attempting to recreate emotion contagion phenomena in small groups of agents, and even studying emotion contagion impact between virtual agents and human participants. Under the belief that emotion contagion in virtual agents might lead to more realistic behaviours on crowds, this work is focused on recreating emotion contagion computational models designed for small groups of agents, and adapting it for crowd simulation context.

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