241 research outputs found

    Genomic selection in rubber tree breeding: A comparison of models and methods for managing G×E interactions

    Get PDF
    Several genomic prediction models combining genotype × environment (G×E) interactions have recently been developed and used for genomic selection (GS) in plant breeding programs. G×E interactions reduce selection accuracy and limit genetic gains in plant breeding. Two data sets were used to compare the prediction abilities of multienvironment G×E genomic models and two kernel methods. Specifically, a linear kernel, or GB (genomic best linear unbiased predictor [GBLUP]), and a nonlinear kernel, or Gaussian kernel (GK), were used to compare the prediction accuracies (PAs) of four genomic prediction models: 1) a single-environment, main genotypic effect model (SM); 2) a multienvironment, main genotypic effect model (MM); 3) a multienvironment, single-variance G×E deviation model (MDs); and 4) a multienvironment, environment-specific variance G×E deviation model (MDe). We evaluated the utility of genomic selection (GS) for 435 individual rubber trees at two sites and genotyped the individuals via genotyping-by-sequencing (GBS) of single-nucleotide polymorphisms (SNPs). Prediction models were used to estimate stem circumference (SC) during the first 4 years of tree development in conjunction with a broad-sense heritability (H2) of 0.60. Applying the model (SM, MM, MDs, and MDe) and kernel method (GB and GK) combinations to the rubber tree data revealed that the multienvironment models were superior to the single-environment genomic models, regardless of the kernel (GB or GK) used, suggesting that introducing interactions between markers and environmental conditions increases the proportion of variance explained by the model and, more importantly, the PA. Compared with the classic breeding method (CBM), methods in which GS is incorporated resulted in a 5-fold increase in response to selection for SC with multienvironment GS (MM, MDe, or MDs). Furthermore, GS resulted in a more balanced selection response for SC and contributed to a reduction in selection time when used in conjunction with traditional genetic breeding programs. Given the rapid advances in genotyping methods and their declining costs and given the overall costs of large-scale progeny testing and shortened breeding cycles, we expect GS to be implemented in rubber tree breeding programs

    RobotAtFactory 4.0: a ROS framework for the SimTwo simulator

    Get PDF
    Robotics competitions encourage the development of solutions to new challenges that emerge in sync with the rise of Industry 4.0. In this context, robotic simulators are employed to facilitate the development of these solutions by disseminating knowledge in robotics, Education 4.0, and STEM. The RobotAtFactory 4.0 competition arises to promote improvements in industrial challenges related to autonomous robots. The official organization provides the simulation scene of the competition through the open-source SimTwo simulator. This paper aims to integrate the SiwTwo simulator with the Robot Operating System (ROS) middleware by developing a framework. This integration facilitates the design of robotic systems since ROS has a vast repository of packages that address common problems in robotics. Thus, competitors can use this framework to develop their solutions through ROS, allowing the simulated and real systems to be integrated.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/05757/2020. The project that gave rise to these results received the support of a fellowship from ”la Caixa” Foundation (ID 100010434). The fellowship code is LCF/BQ/DI20/11780028.info:eu-repo/semantics/publishedVersio

    Finite Element Modal Analysis of Transient Water Flow in Aquifers

    Get PDF
    In this paper a modal superposition method is applied for the numerical modeling of aquifers. The proximity of aquifers to populated regions requires special care in their management to avoid problems that affect the quantity and quality of the water they supply. To contribute to the management of this type of natural resource, we propose a numerical strategy based on modal analysis using the finite element method. This procedure assist water production scenarios, performing the mass balance where water extraction is done through wells, in aquifers that are subject to natural recharge. This mathematical procedure is based on the modal superposition for transient flow in porous media. To evaluate its efficiency, this strategy was compared with the classical finite element method. The advantage of the proposed method resides in the possibility of reusing the properties of the global matrix of the finite element method in transient problems, for different production conditions given by the distributed recharge and by the water extraction rate from the wells, solving the numerical problem with a more efficient use of computational resources. This strategy is useful in studies of uncertainty quantification, history matching and optimization of water production in aquifers, since these types of analysis are resource intensive for the very large number of numerical simulations required for these scenarios

    Metodologia heurística construtiva para alocação de bancos de capacitores em sistemas de distribuição de energia elétrica

    Get PDF
    This paper presents a heuristic constructive algorithm to solve the discrete capacitor size and allocation problem in distribution systems. Initially the discrete nature of the capacitor allocation problem is mitigated by using a sigmoid function in the [0,1] interval which is incorporated into the optimum power flow (OPF) through modifications in the power flow equations. The proposed algorithm uses the primal-dual interior point technique to solve the OPF problem. Finally, the sensitivity obtained by sigmoid function which is weighted by the reactive loading of the distribution system, determines step by step the location, size and number of capacitors to be installed in the distribution system. The proposed technique is applied in two distribution systems. The results obtained are compared with the ones obtained using the genetic algorithm.Este artigo apresenta um algoritmo heurístico construtivo para a resolução do problema referente à alocação ótima de bancos fixos de capacitores em sistemas de distribuição. Inicialmente a natureza discreta do problema de alocação de capacitores é mitigada através do uso de uma função sigmoidal no intervalo [0,1] que é incorporada ao problema de fluxo de potência ótimo (FPO) através de modificações nas equações de fluxo de potência. O algoritmo proposto utiliza a técnica primal-dual de pontos interiores como ferramenta de solução do FPO. Baseado na sensibilidade fornecida pela função sigmoidal ponderada pelo carregamento da potência reativa do sistema de distribuição, a metodologia heurística proposta determina passo a passo a localização, a capacidade e o número de capacitores a serem instalados no sistema. A técnica proposta é aplicada a dois sistemas de distribuição de energia. Os resultados são comparados com os resultados obitidos através de um algoritmo genético

    Percepções de Estudantes sobre uma Mostra de Experimentos de Física Realizada em um Evento de Extensão.

    Get PDF
    Pretendemos avaliar quais as percepções dos participantes sobre uma mostra de experimentos de física bem como quais experimentos os participantes apresentaram facilidade de entendimento. Utilizamos um questionário para coletar os dados. Os participantes consideraram válida a iniciativa dos experimentos e ficaram satisfeitos com as explicações fornecidas pelos professores mediadores. As teorias associadas às experiências do circuito elétrico e motor elétrico obtiveram maior facilidade de entendimento dos participantes, enquanto os mesmos obtiveram dificuldade para compreender a teoria relacionada à atividade proposta no movimento no trilho de ar (colisão) e a prática experimental de difração. Sugestões de experimentos foram fornecidas pelos participantes para a próxima mostra de experimentos; como, por exemplo, experimentos relacionados à geração e transmissão de energia elétrica; bobina de tesla; toróide e experimentos de eletrônica. Como perspectiva futura, pretendemos orientar os participantes na construção de alguns experimentos de física, para que os mesmos possam ser doados para escolas públicas do ensino fundamental e médio, que carecem de laboratório de física

    Distribution system restoration using optimal power flow

    Get PDF
    This paper proposes a methodology to solve the Distribution System restoration problem after a fault. This is a Mix Integer Non-Linear optimization problem which poses considerable challenges to traditional methods. The approach described in this paper models the discrete variables of the problem as continuous functions, thus the problem can be solved using the Primal-Dual Interior Point method. The proposed methodology uses graph theory to identify isolated areas and loops in the system. System switches are closed based on a index, obtained from an Optimum Power Flow (OPF) algorithm. The problem is solved step-by-step, providing a feasible switching operation sequence. The proposed method are tested and comparisons show the efficcience and robustness of the algorithm.Este artigo apresenta uma metodologia para solução do problema de restabelecimento de Sistemas de Distribuição de Energia após a ocorrência de um defeito. Trata-se de um problema de programação não linear inteira mista de difícil solução pelos métodos tradicionais. Na metodologia proposta, as variáveis discretas do problema são modeladas como uma função contínua, permitindo que o problema possa ser resolvido utilizando-se o Método Primal-Dual de Pontos Interiores. No processo de solução, inicialmente utiliza-se teoria de grafos para determinar as áreas isoladas e os laços no sistema. Em seguida, as chaves são fechadas com base em um índice obtido através do Fluxo de Potência Ótimo (FPO). O problema é resolvido passo a passo de tal forma que uma sequência viável de operação é fornecida no final do processo. Testes e comparações são realizados mostrando a eficiência da metodologia proposta

    Determinação da operação de unidades térmicas para o estudo de Unit Commitment através de uma análise de sensibilidade

    Get PDF
    This paper proposes the utilization of a new sensibility index to organize a priority list for the solution of the Unit Commitment problem. The discrete nature of the operational decisions is mitigated through a continuous function. Thus the new index is derived from the lagrangian multipliers and the non-linear optimization problem is solved using the interior point primal-dual method. The priority list is obtained as a by-product of the lagrangian multipliers associated with the "ON-OFF" decision. The efficiency of the proposed methodology is demonstrated through several tests.Este artigo propõe a utilização de um novo índice de sensibilidade à elaboração de uma lista de prioridade para a resolução do problema de "Unit Commitment". O novo índice é obtido através dos multiplicadores de Lagrange associado às variáveis discretas inerentes ao problema, as quais são mitigadas através de uma função contínua. Desta forma, o problema de otimização não linear é resolvido através da utilização da metodologia primal-dual de pontos interiores e como subproduto têm-se os multiplicadores de Lagrange associados às variáveis de decisão "ON-OFF" para a elaboração de uma lista de prioridade. Os resultados obtidos mostram a eficiência da metodologia proposta

    Classifying radius fractures with X-ray and tomography imaging

    Get PDF
    INTRODUÇÃO: Este estudo avaliou a confiabilidade interobservador da radiografia simples versus tomografia computadorizada para as classificações Universal e AO em fraturas do rádio distal. PACIENTES e MÉTODOS: Cinco observadores classificaram 21 fraturas do rádio distal utilizando radiografias e tomografias independentemente. O índice Kappa foi utilizado para estabelecer o nível de concordância entre os observadores. RESULTADOS: A confiabilidade interobservador da classificação Universal foi moderada e a confiabilidade interobservador da classificação AO foi baixa. Reduzindo a clas-sificação AO a nove categorias e às três categorias básicas houve melhora do nível de confiabilidade para "moderado". Não houve diferença entre a confiabilidade interobservador da classificação Universal baseada em imagens radiográficas em comparação com a classificação Universal baseada em imagens tomográficas. A confiabilidade interobservador da classificação AO baseada em radiografias simples foi significativamente maior que a confiabilidade interobservador da classificação AO baseada apenas em tomografias computadorizadas. CONCLUSÃO: A partir destes dados, concluímos que classificar fraturas do rádio distal utilizando tomografias computadorizadas sem o auxílio das radiografias simples não traz benefício.INTRODUCTION: This study evaluated the interobserver reliability of plain radiograpy versus computed tomography (CT) for the Universal and AO classification systems for distal radius fractures. PATIENTS AND METHODS: Five observers classified 21 sets of distal radius fractures using plain radiographs and CT independently. Kappa statistics were used to establish a relative level of agreement between observers for both readings. RESULTS: Interobserver agreement was rated as moderate for the Universal classification and poor for the AO classification. Reducing the AO system to 9 categories and to its three main types reliability was raised to a "moderate" level. No difference was found for interobserver reliability between the Universal classification using plain radiographs and the Universal classification using computed tomography. Interobserver reliability of the AO classification system using plain radiographs was significantly higher than the interobserver reliability of the AO classification system using only computed tomography. CONCLUSION: From these data, we conclude that classification of distal radius fractures using CT scanning without plain radiographs is not beneficial

    Phenotypic adaptability of cotton genotypes to the brazilian cerrado for yield and fiber quality

    Get PDF
    Studies on the adaptability and stability are fundamental for plant breeding as they are an alternative to reduce the effects of genotypes x environments interaction (GxE). Moreover, they help identify cultivars with predictable behavior, which are responsive to environmental improvements, subsidizing cultivar recommendation. This study aimed to investigate the genotypes x environments interaction in cotton genotypes grown in the Brazilian Cerrado and identify genotypes for favorable and unfavorable environments. During the 2013/2014 and 2014/2015 seasons, 19 competition trials were carried out with cotton in a randomized block design, with 12 treatments, and four replications. The traits cotton seed yield, fiber percentage, fiber length, and fiber strength were evaluated. Results revealed significant GxE interaction for all the fiber traits evaluated. Genotype BRS 369 RF revealed general adaptability and high predictability for the fiber traits evaluated
    corecore