Fractional Integration and Its Influence on Unit Root and Co- Integration Analysis

Este estudo avalia o poder dos testes tradicionais de raízes unitárias e de co-integração, quando aplicados em processos estocásticos fracionariamente integrados no intervalo 0 ≤ d ≤ 1 . Foram conduzidas simulações de Monte Carlo para avaliar a sensibilidade dos testes de raízes unitárias em distinguir as condições I(1) − I(0) das condições fracionárias. Nossos resultados mostraram que os testes possuem individualmente baixo poder quando aplicados em séries pequenas com memória longa. No entanto, percebemos que sob determinadas condições os testes de raízes unitárias podem apresentar resultados que podem ajudar a evitar o problema da super-diferenciação na análise de estacionariedade das séries. Na análise de co-integração, considerando alternativas fracionárias no intervalo 0 ≤ d ≤ 0.6, encontramos condições que podem conduzir a resultados satisfatóriosThis study assesses the power of traditional unit root and co-integration tests when they are applied to fractionally integrated stochastic processes in the 0 ≤ d ≤ 1 range. Monte Carlo simulations were conducted to evaluate the sensitivity of the unit root tests in distinguishing the I(1)−I(0) conditions of the fractional conditions. Our results showed that unit root tests have individually low power when applied to small sample series with long-memory. However, we found that under specific conditions the unit root tests can produce results that can help avoid the over-differentiation problem. In the co-integration analysis for fractional alternatives on the interval 0 ≤ d ≤ 0.6, we found some conditions that can lead to satisfactory result

An Evidence-based Roadmap for IoT Software Systems Engineering

Context: The Internet of Things (IoT) has brought expectations for software inclusion in everyday objects. However, it has challenges and requires multidisciplinary technical knowledge involving different areas that should be combined to enable IoT software systems engineering. Goal: To present an evidence-based roadmap for IoT development to support developers in specifying, designing, and implementing IoT systems. Method: An iterative approach based on experimental studies to acquire evidence to define the IoT Roadmap. Next, the Systems Engineering Body of Knowledge life cycle was used to organize the roadmap and set temporal dimensions for IoT software systems engineering. Results: The studies revealed seven IoT Facets influencing IoT development. The IoT Roadmap comprises 117 items organized into 29 categories representing different concerns for each Facet. In addition, an experimental study was conducted observing a real case of a healthcare IoT project, indicating the roadmap applicability. Conclusions: The IoT Roadmap can be a feasible instrument to assist IoT software systems engineering because it can (a) support researchers and practitioners in understanding and characterizing the IoT and (b) provide a checklist to identify the applicable recommendations for engineering IoT software systems

Design and evaluation of new overview screens for the labihs simulator

The development and evaluation of Human-System Interfaces (HSIs) for control rooms is a research area at the Human-System Interface Laboratory (LABIHS). The main objective of this laboratory is to develop and evaluate projects of HSIs for industrial plants using different methodology construction. The evaluation of the interfaces is carried out in the LABIHS simulator at the Nuclear Engineering Institute (IEN). Previous evaluation of the overview screen of the nuclear power plant (NPP) simulator of the LABIHS showed the necessity of additional information to reduce the operator workload. To overcome this issue, a set of three 52-inch LCD TV was acquired to replace the projector in the task of showing the overview screen to the simulator operators. A new set of screens was developed to gather information in the three LCD screens. The approach used on the development of the new screens was based on human factors guidelines and recommendations. The objective of this work is present the design of these new overview screens and to evaluate their contribution to reduce the operators mental workload in this new scenario

Titanium nanoparticles in sedimented dust aggregates from urban children’s parks around coal ashes wastes

Recently, an increased interest in nanoscience applications can be observed in various fields. Soils around coal power plants may contain potentially hazardous elements (PHEs) and nanoparticles (NPs), which can be neo-produced pollutants or can be a product of industrial coal utilization. While titanium (Ti)-NPs contact is a worldwide concern, transference of Ti-NPs to infants as well as their human health impact is still imprecise. In general, the toxicity and the human health risk assessment associated with the presence of some Ti-NPs, needs to be determined with a robust and fast analytical methodology. The mode of occurrences of Ti-NPs in children’s playgrounds were evaluated by advanced electron microscopy techniques (field emission scanning electron microscope-FE-SEM and high resolution transmission electron microscope-HR-TEM) coupled with an energy dispersive X-ray microanalysis system (EDS); Raman Spectroscopy (RS); and X-Ray Diffractions (XRD). The reported data showed that when the size of the NPs reduced, the ability of sedimented dust aggregates to transport PHEs increased. Carbonaceous matter and amorphous silica were the main factors that influenced the distribution of PHEs among the studied Ti-NPs aggregates. Together, the data indicate that the proportions of PHEs in sedimented urban dust in the urban area around coal power plants are mainly due to emissions related to vehicle traffic and the coal industry, representing immediate environmental risks and long-term health risks. Therefore, actions are required to monitor and mitigate the impact of Ti-NPs aggregates in the urban area and nearby ecosystems. Such pollutants are necessary to be observed as children represent a susceptible cluster likened to adults. The currently estimated risk can be influenced by factors such as absorption, form of Ti-NPs, particle fraction, particle size, and physico-geochemical properties in relation to toxicity, among others. Analysis of actual particle concentrations in human organs, as well as organ concentrations and effects in liver and the reproductive system after chronic exposure to well-characterized Ti-NPs in animals are recommended to refine this assessment

Nanoparticles from evaporite materials in Colombian coal mine drainages

Ultrathin and nanometric materials (minerals and amorphous phases) are detected in transitory deposits of potential hazardous elements (PHEs), especially in acidic coal mine drainages. The main goal of this work was to evaluate the occurrence of PHEs in nanoparticles (NPs) in evaporative structures in coal mining areas with high concentrations of PHEs. The precipitates were sampled in several coal mining areas in Colombia, with the purpose of evaluating the geochemical and environmental structures. In the present work, to better diagnose areas affected by coal mining, an innovative analytical procedure is proposed to define the association between PHEs in mine drainage sediments. The procedure includes the analytical study with X-Ray Diffraction (XRD) and advanced electron microscopy, before and after a series of sequential extractions to separate amorphous, magnetic, and crystalline compounds. Of the three main types of precipitates identified, the yellowish precipitates had the highest amounts of PHEs while the white precipitates had only small amounts of PHEs and the greenish precipitates contained TiO2 nanoparticles. The results from this study will be usable for more than fifty countries that have coal mine drainages

Os limites fiscais e or??ament??rios da reforma gerencial nos estados: o exemplo de Minas Gerais

O artigo analisa os resultados obtidos com a implanta????o do Choque de Gest??o em Minas Gerais, quanto ?? capacidade de produzir os resultados esperados nos aspectos or??ament??rio e fiscal e de sustent??-los no m??dio prazo. ?? analisada a evolu????o da execu????o or??ament??ria estadual, de 2004 a 2011, tendo como foco o percentual dos investimentos e a forma de financiamento das despesas estaduais, com base na reforma gerencial iniciada em 2003. Foi realizada uma pesquisa quantitativa para avalia????o da evolu????o de indicadores fiscais e or??ament??rios, tais como Resultado Prim??rio e Nominal, Resultado Prim??rio Marginal, Resultado Operacional L??quido, ??ndice de Investimento, Resultado Fiscal dos Recursos Ordin??rios, entre outros. Valendo-se da pesquisa, conclui-se que, quanto ?? situa????o fiscal do Estado de Minas Gerais, o panorama n??o se mostra muito favor??vel, apesar dos Resultados Or??ament??rios Fiscais positivos desde 2004. Destaca-se a redu????o das taxas de resultado prim??rio marginal obtidas, a amplia????o dos N??veis de Endividamento Estadual e a utiliza????o dos recursos de fontes vinculadas e diretamente arrecadadas como forma de garantir os super??vits fiscais or??ament??rios. Sob a ??tica da amplia????o das receitas estaduais, constatase, a partir de 2009, redu????o no ??ndice de arrecada????o estadual. Quanto ?? redu????o das despesas e ?? melhoria da qualidade do gasto p??blico, observa-se o ano de 2004 como um per??odo de ajuste; por??m, os resultados sugerem que as melhorias percebidas nos anos iniciais ap??s o denominado ???Choque de Gest??o??? n??o se perpetuaram e n??o podem ser considerados como duradouros e capazes de produzir resultados de m??dio prazo

Ex vivo exposure to titanium dioxide and silver nanoparticles mildly affect sperm of gilthead seabream (Sparus aurata) - A multiparameter spermiotoxicity approach

Nanoparticles (NP) are potentially repmtoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO2: 10 to 10,000 mu g.L-1) and silver NP (Ag: 0.25 to 250 mu g.L-1) on the sperm of gilthead seabream (Sparus aurata). We performed short-term direct exposures (ex vivo) and evaluated sperm motility, head morphometry, mitochondrial function, antioxidant responses and DNA integrity. No alteration in sperm motility (except for supra environmental Ag NP concentration), head morphometry, mitochondrial function, and DNA integrity occurred. However, depletion of all antioxidants occurred after exposure to TiO2 NP, whereas SOD decreased after exposure to Ag NP (lowest and intermediate concentration). Considering our results, the decrease in antioxidants did not indicate vulnerability towards oxidative stress. TiO2 NP and Ag NP induced low spermiotoxicity, without proven relevant ecological impacts.info:eu-repo/semantics/publishedVersio