Mobile Paving System (MPS): A New Large Scale Freeform Fabrication Method

In the last decade, significant opportunities for automation have been identified in the area of construction. Soaring labor and material costs have driven multiple research efforts in construction automation. In this paper, we present a novel means for construction automation that involves the fusion of the rapid prototyping, controls and mechatronics technologies. The resultant autonomous construction mechanism has been designed for commercial applications. Mobile Paving System (MPS) is a new freeform fabrication process which is capable of rapidly producing variable profiles such as curbs and sidewalks out of materials like cement and asphalt. Path generation and guidance of the construction operation is controlled by a mobile robot. This article presents an overview of research and development efforts that are aimed at establishing the feasibility and the potential of the process.Mechanical Engineerin

Intramolecular radical aromatic substitution reactions

This thesis is divided into three chapters. Chapter One presents a review on ipso substitution in aromatic and heteroaromatic rings, and is divided in two parts. The first is concerned with intermolecular ipso substitution reactions and the second describes the work that has been done on the intramolecular reactions. Chapter Two describes the advances of an intramolecular free radical ipso substitution strategy which uses a sulfonyl moiety as an ipso nucleofuge. The reaction of an aryl radical with a sulfonyl substituted acceptor ring, with differing substituents on the acceptor ring and tethering chains of different nature and size, is discussed. A strong effect on the promotion of ipso substitution was found with compounds where an ortho substituent to the sulfonyl substituted position was present. In the absence of an ortho substituent, preferential attack occurs in order to give the more stable radical. The nature of the bridge between the two aromatic rings is also an important factor, and a slight change in the strain or conformation can change the course of the reaction. With simple chains was observed that in 1,5-ipso substitution reactions, a nitrogen atom is a more efficient ipso director than an oxygen atom, which in turn is better than a methylene unit. 1,6-Ipso substitution reactions were shown to be less efficient processes. Several linking chains, resulting from the combination of nitrogen, oxygen, methylene and carbonyl units were analysed, and in general ipso substitution products could be obtained, although, in some cases, only by the strategical introduction of ortho substituents. A preliminary study on 1,5-ipso substitution reactions of a-carbonyl radicals was undertaken, in order to optimise the reaction conditions. Reactions involving tin compounds, transition metals and xanthates were studied. When tin hydride was used, the formation of indolone derivatives, by a sequential 1,5-ipso substitution / 1,5-addition of the intermediate amidyl radical to the aromatic ring was observed. The temperature of the reaction was shown to be an important factor, as other competitive processes, such as reduction or β-scission can also occur. Chapter Three provides a formal account of the experimental results and procedures

Chemical abundances of stars with brown-dwarf companions

It is well-known that stars with giant planets are on average more metal-rich than stars without giant planets, whereas stars with detected low-mass planets do not need to be metal-rich. With the aim of studying the weak boundary that separates giant planets and brown dwarfs (BDs) and their formation mechanism, we analyze the spectra of a sample of stars with already confirmed BD companions both by radial velocity and astrometry. We employ standard and automatic tools to perform an EW-based analysis and to derive chemical abundances from CORALIE spectra of stars with BD companions. We compare these abundances with those of stars without detected planets and with low-mass and giant-mass planets. We find that stars with BDs do not have metallicities and chemical abundances similar to those of giant-planet hosts but they resemble the composition of stars with low-mass planets. The distribution of mean abundances of $\alpha$-elements and iron peak elements of stars with BDs exhibit a peak at about solar abundance whereas for stars with low-mass and high-mass planets the [X$_\alpha$/H] and [X$_{\rm Fe}$/H] peak abundances remain at $\sim -0.1$~dex and $\sim +0.15$~dex, respectively. We display these element abundances for stars with low-mass and high-mass planets, and BDs versus the minimum mass, $m_C \sin i$, of the most-massive substellar companion in each system, and we find a maximum in $\alpha$-element as well as Fe-peak abundances at $m_C \sin i \sim 1.35\pm 0.20$ jupiter masses. We discuss the implication of these results in the context of the formation scenario of BDs in comparison with that of giant planets.Comment: Accepted for publication in Astronomy & Astrophysic

Evaluation of CNN architectures for gait recognition based on optical flow maps

This work targets people identification in video based on the way they walk (\ie gait) by using deep learning architectures. We explore the use of convolutional neural networks (CNN) for learning high-level descriptors from low-level motion features (\ie optical flow components). The low number of training samples for each subject and the use of a test set containing subjects different from the training ones makes the search of a good CNN architecture a challenging task.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

More than Words: Leaders' Speech and Risky Behavior During a Pandemic

How do political leader's words and actions affect people's behavior? We address this question in the context of Brazil by combining electoral data and geo-localized mobile phone data for more than 60 million devices throughout the entire country. We find that after Brazil's president publicly and emphatically dismisses the risks associated with the COVID-19 Pandemic and advises against isolation, social distancing measures of citizens in pro-government localities reduce relative to those places in which his support is weaker, while pre-event effects are insignificant. The impact is large and robust to different empirical model specifications. We also find suggestive evidence that this impact is driven by localities with relatively higher levels of media penetration

Volatility spillover effect of pan-Asia’s property portfolio markets

This study assesses the spillover effect of the listed property companies that cover pan-Asian countries, namely Malaysia, Thailand, Indonesia, Singapore, Vietnam, South Korea, Japan, China, the Philippines, and Hong Kong. The impact of market integration will create a spillover effect to the countries’ economic performances, in particular the property market. As macroeconomic factors have high correlation with the performance of property security markets, it is therefore important to study the spillover effect by integrating the macroeconomic factors. This study has employed the exponential generalised autoregressive conditional heteroscedasticity (EGARCH) technique to develop the volatility spillover effect among pan-Asian countries. The results reveal high volatility of listed property companies recorded in Hong Kong and China, while Singapore, The Philippines and Japan have shown low volatility spillovers. In terms of macroeconomic factors, gross domestic product (GDP) and money supply (MS) are the most significant factors in influencing the volatility spillover effect among pan-Asian countries. From the standpoint of regional investors, the volatility spillover characteristics of pan-Asian countries will aid property stakeholders in the region in developing their own methods for making investment decisions in the property security market. Furthermore, in uncertain conditions of the financial market, this study will elevate the transparency of the pan-Asian property portfolio market by providing information on the property market volatility spillovers.info:eu-repo/semantics/publishedVersio

Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain

Although recent studies have revealed more widespread occurrences of magnetofossils in pre-Quaternary sediments than have been previously reported, their significance for paleomagnetic and paleoenvironmental studies is not fully understood. We present a paleo- and rock-magnetic study of late Miocene marine sediments recovered from the Guadalquivir Basin (SW Spain). Well-defined paleomagnetic directions provide a robust magnetostratigraphic chronology for the two studied sediment cores. Rock magnetic results indicate the dominance of intact magnetosome chains throughout the studied sediments. These results provide a link between the highest-quality paleomagnetic directions and higher magnetofossil abundances. We interpret that bacterial magnetite formed in the surface sediment mixed layer and that these magnetic particles gave rise to a paleomagnetic signal in the same way as detrital grains. They, therefore, carry a magnetization that is essentially identical to a post-depositional remanent magnetization, which we term a bio-depositional remanent magnetization. Some studied polarity reversals record paleomagnetic directions with an apparent 60-70 kyr recording delay. Magnetofossils in these cases are interpreted to carry a biogeochemical remanent magnetization that is locked in at greater depth in the sediment column. A sharp decrease in magnetofossil abundance toward the middle of the studied boreholes coincides broadly with a major rise in sediment accumulation rates near the onset of the Messinian salinity crisis (MSC), an event caused by interruption of the connection between the Mediterranean Sea and the Atlantic Ocean. This correlation appears to have resulted from dilution of magnetofossils by enhanced terrigenous inputs that were driven, in turn, by sedimentary changes triggered in the basin at the onset of the MSC. Our results highlight the importance of magnetofossils as carriers of high-quality paleomagnetic and paleoenvironmental signals even in dominantly terrigenous sediments.This study was funded by the Guadaltyc project (MINECO, CGL2012–30875), ARC grant DP120103952, and NSFC grant 41374073

Mathematical Models for Estimating the Risk of vCJD Transmission

We present two different simple models for vCJD transmission by blood transfusion. Both models indicate that transfusions alone are unlikely to cause more than a few infections, unless the number of primary cases increases. To improve our models, future work should pursue data collection, empirical estimation of the model parameters, and examination of the underlying assumptions of our frameworks. Further improvements could also include examining susceptibility to vCJD infection by age group and iatrogenic infections introduced through surgical instruments. Regarding the latter, it may be worthwhile to conduct experiments to quantify the transmission of prions from an infected surgical instrument after repeated sterilization procedures

Modelado y Resolución del Problema Dinámico Inverso y Directo en Tiempo Real de Robots Industriales

ResumenEste trabajo presenta el desarrollo y la validación de una metodología que permite el modelado y la resolución del problema dinámico en tiempo real de robots manipuladores. La ecuación dinámica del robot está basada en la ecuación de movimiento de Gibbs-Appell, proporcionando un conjunto de ecuaciones bien estructuradas que pueden ser calculadas en tiempo real.El artículo aborda el cálculo e implementación del problema dinámico directo e inverso de robots, aplicándose al control en tiempo real de un robot industrial PUMA 560 equipado con una arquitectura abierta de control basada en un computador personal industrial