SRflow: Deep learning based super-resolution of 4D-flow MRI data

Exploiting 4D-flow magnetic resonance imaging (MRI) data to quantify hemodynamics requires an adequate spatio-temporal vector field resolution at a low noise level. To address this challenge, we provide a learned solution to super-resolve in vivo 4D-flow MRI data at a post-processing level. We propose a deep convolutional neural network (CNN) that learns the inter-scale relationship of the velocity vector map and leverages an efficient residual learning scheme to make it computationally feasible. A novel, direction-sensitive, and robust loss function is crucial to learning vector-field data. We present a detailed comparative study between the proposed super-resolution and the conventional cubic B-spline based vector-field super-resolution. Our method improves the peak-velocity to noise ratio of the flow field by 10 and 30% for in vivo cardiovascular and cerebrovascular data, respectively, for 4 × super-resolution over the state-of-the-art cubic B-spline. Significantly, our method offers 10x faster inference over the cubic B-spline. The proposed approach for super-resolution of 4D-flow data would potentially improve the subsequent calculation of hemodynamic quantities

Velocity-To-Pressure (V2P) - Net: Inferring Relative Pressures from Time-Varying 3D Fluid Flow Velocities

Pressure inference from a series of velocity fields is a common problem arising in medical imaging when analyzing 4D data. Traditional approaches primarily rely on a numerical scheme to solve the pressure-Poisson equation to obtain a dense pressure inference. This involves heavy expert intervention at each stage and requires significant computational resources. Concurrently, the application of current machine learning algorithms for solving partial differential equations is limited to domains with simple boundary conditions. We address these challenges in this paper and present V2P-Net: a novel, neural-network-based approach as an alternative method for inferring pressure from the observed velocity fields. We design an end-to-end hybrid-network architecture motivated by the conventional Navier-Stokes solver, which encapsulates the complex boundary conditions. It achieves accurate pressure estimation compared to the reference numerical solver for simulated flow data in multiple complex geometries of human in-vivo vessels

Aplicação do earned value em projetos complexos - um estudo de caso na EMBRAER On the use of the earned value management system approach for complex projects in the brazilian aircraft industry

O gerenciamento do Earned Value vem obtendo aceitação crescente nas empresas e entre profissionais tais como gerentes de projetos e funcionais, devido à sua efetividade no controle dos resultados do projeto. Earned Value é definido como uma ferramenta de controle que permite avaliar simultaneamente de maneira quantitativa como se encontram os custos e prazos em uma data de controle, permitindo também prever a data de término e o valor gasto (VARGAS, 2005). Este artigo avalia a aplicabilidade do earned value como ferramenta de controle de projetos aeronáuticos na EMBRAER. Contribui também para a aplicação do earned value no controle de projetos complexos. Utilizam-se como técnicas de coleta de dados: entrevistas, observações e análise documental. Conclui-se que o earned value é utilizado apenas nos projetos da área de aviação de defesa, por ser uma exigência contratual. O uso do earned value nas áreas de programas executivos e comerciais restringe-se às fases de definição conjunta, projeto detalhado e certificação, pois o escopo do projeto é bem definido, o cronograma é detalhado e os custos são previstos e obtidos com maior acuidade. Nas demais fases de desenvolvimento do produto, o uso do earned value é restrito, devido principalmente às constantes alterações de escopo do produto e do projeto.<br>Earned value management has been increasingly used by companies as well as by functional and project managers due to its effectiveness in controlling project results. It is defined as a control tool that enables a quantitative and simultaneous evaluation of the costs and process time within a pre-scheduled date as well as predicting the deadline and the total value spent (VARGAS, 2005).This study evaluates the earned value applicability as a tool to control aeronautical projects at EMBRAER, A Brazilian Aeronautical Company. It is also concerned with the application of earned value in the control of complex projects. The data were gathered through interviews, observations and document analysis. The results show that The Earned Value is used only in the defense aviation projects since it is a contractual obligation. Its use in executive and commercial areas is restricted to the combined definition stages, detailed project, and certification because the scope of the project is well defined, the schedule is detailed, and the costs are foreseen and fairly accurate. In the other stages of the product development, the use of earned value is restricted mainly because of the frequent changes of the scope of the product and project

Níveis de silicato de cálcio e magnésio na produção das gramídeas Marandu e Tanzânia cultivadas em um Neossolo Quartzarênico Level of calcium and magnesium silicate in the yield of Marandu grass and Tanzania grass cultivated in one Quartzsandy Neosoil

O estudo foi conduzido em casa-de-vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras, Lavras-MG, com o objetivo de avaliar o efeito da correção da acidez do solo, por meio da aplicação de níveis de silicato de Ca e Mg, na produção das gramíneas Brachiaria brizantha cv. Marandu e Panicum maximum cv. Tanzânia-1 cultivadas em solo Neossolo Quartzarênico ortic. O delineamento experimental utilizado foi blocos ao acaso, em esquema fatorial 2 x 5 com quatro repetições, sendo duas forrageiras e cinco níveis de saturação por bases (V% original, 40, 60, 80 e 100%). Cada unidade experimental correspondeu a um vaso sem furos, com capacidade para 4,0 dm³ de solo, totalizando 40 vasos. Foram avaliadas as produções de MS por corte (PMS) e total (PTMS), a altura e o número de perfilhos. Não houve variação entre as gramíneas em altura de perfilhos. O Tanzânia foi superior ao Marandu em PMS e número de perfilhos. Houve aumento linear na PMS, PTMS e altura de perfilhos. Conclui-se que ambas as gramíneas responderam de forma positiva à elevação dos níveis de V%, em PMS, até 54,8%. O Tanzânia produziu mais MS em relação ao Marandu.<br>This study was conducted in a greenhouse of the Soil Science Department at Universidade Federal de Lavras, Lavras-MG, with the purpose of evaluating the effect of the soil correction acidity, by the application of Ca and Mg silicate levels, in the production of grasses Brachiaria brizantha cv. Marandu and Panicum maximum cv. Tanzânia-1 cultivated in Quartzsandy Neosoil ortic. The experimental design was a randomized complete block, in 2 x 5 factorial scheme with four replicates, being two forages and five levels of base saturation (BS%); (original BS, 40, 60, 80 and 100%). Each experimental unit corresponded to a pot with a capacity of 4.0 dm³ of soil, totalizing 40 pots. The dry matter yield (DMY) for cut and total (TDMY), height and number of tillers were evaluated. There were no variations among the grasses in tiller height. Tanzania grass was superior to Marandu grass in DMY and tiller number. There were linear increases in DMY, TDMY and tiller height as the BS% levels increased. It follows that both grasses responded positively to the rise of BS% in DMY until 54.8%. Tanzania grass produced more DM in relation to Marandu grass