6D Pose Estimation using an Improved Method based on Point Pair Features

The Point Pair Feature (Drost et al. 2010) has been one of the most successful 6D pose estimation method among model-based approaches as an efficient, integrated and compromise alternative to the traditional local and global pipelines. During the last years, several variations of the algorithm have been proposed. Among these extensions, the solution introduced by Hinterstoisser et al. (2016) is a major contribution. This work presents a variation of this PPF method applied to the SIXD Challenge datasets presented at the 3rd International Workshop on Recovering 6D Object Pose held at the ICCV 2017. We report an average recall of 0.77 for all datasets and overall recall of 0.82, 0.67, 0.85, 0.37, 0.97 and 0.96 for hinterstoisser, tless, tudlight, rutgers, tejani and doumanoglou datasets, respectively

Examining sorption of perfluoroalkyl substances (PFAS) in biochars and other carbon-rich materials

The use of carbon-rich sorbents to remove and/or immobilize perfluoroalkyl substances (PFAS) in contaminated environmental scenarios is attracting increasing interest. The identification of key sorbent properties responsible for PFAS sorption and the development of models that can predict the distribution coefficients (Kd) for PFAS sorption in these materials are crucial in the screening of candidate materials for environmental remediation. In this study, sorption kinetics, sorption isotherms, and the effects of pH, calcium concentration and dissolved organic carbon (DOC) content on PFAS sorption were evaluated in four representative carbon-rich materials: two biochars with contrasting properties, a compost, and charcoal fines rejected by the metallurgical industry. Subsequently, the sorption of seven PFAS with numbers of fluorinated carbons ranging from 4 to 11 was evaluated in a total of ten carbon-rich materials, including activated carbons, so as to build up a Kd prediction model. The sorption of PFAS increased with greater fluorinated chain length, suggesting that hydrophobic interactions play a major role in sorption and electrostatic interactions a minor one. These results were confirmed by a principal component analysis, which revealed that the CORG/O molar ratio and the specific surface area of the material were the two main sorbent properties affecting PFAS sorption. Furthermore, the DOC content in solution had a negative effect on PFAS sorption. Using this information, a simple Kd prediction model applicable to a wide range of materials and PFAS was developed, using only a few easily-derived physicochemical properties of sorbent (CORG/O molar ratio and SSA) and PFAS (number of CF2), and was externally validated with data gathered from the literature

Optimal collapse simulator for three-dimensional frames

In this work a limit analysis for 3D structures software package is presented. The goal is to obtain for a certain structure the load factor λ that applied to the external loads induces collapse to the structure. The static theorem of limit analysis is the theoretical basis for the Structural Collapse Simulator (SCS), that is finding a stress distribution in equilibrium that does not violate yield criteria anywhere. The limit analysis is developed and written as a Linear Programming Problem, which consists of the maximization of the collapse load factor subject to equilibrium and yield criteria. The Structural Collapse Simulator has been applied to several types of structures to assess its capabilities on world applications

ESTUDO DE ALTERAÇÕES EM PROJETOS CIVIS EM FASE DE EXECUÇÃO

Este artigo apresenta investigação das alterações em projetos civis (arquitetura, estrutura, elétrico, hidrossanitário) em fase de execução, a partir de estudos de caso previamente definidos, e que pudessem representar os cenários atuais da construção civil no Brasil. A partir da revisão bibliográfica, cujo levantamento pode mostrar uma evolução histórica de alguns procedimentos, foi possível identificar várias causas que ainda contribuem para o cenário atual, bastante engessado e muitas vezes avesso a algumas mudanças. Todo esse processo de produção (de projetos) e execução (obras) encontra-se bastante fragmentado, havendo pouca ou nenhuma inter-relação entre as partes envolvidas na maioria dos casos, provocando alterações de toda ordem, comprovando, assim, a atualidade dessa pesquisa. Os resultados encontrados poderão balisar procedimentos futuros, como forma de possibilitar maiores avanços na construção civil

Full-Utilization Learning Lean

This paper reviews trends in component-manufacturing employment, wages, and productivity in union and nonunion shops and shows why a sharp increase in productivity growth, especially in union shops, is necessary if a large number of high-wage jobs are to be preserved. It also explains international and local unions' varied strategies that attempt to preserve jobs and/or raise productivity. Drawing on case study research on production processes in component manufacturing, the paper then argues for a model of industrial production, "full-utilization learning lean," that has the potential to raise productivity and preserve a large number of high-wage manufacturing jobs. This model combines lean production, continuous learning and substantive participation by production workers, and high levels of capacity utilization. The paper suggests public policies and union strategies that can spread this model

Conselho de acompanhamento e controle social do FUNDEF do Estado do Rio Grande do Sul : Conselho do FUNDEF-RS

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