Optimal routing on complex networks

We present a novel heuristic algorithm for routing optimization on complex networks. Previously proposed routing optimization algorithms aim at avoiding or reducing link overload. Our algorithm balances traffic on a network by minimizing the maximum node betweenness with as little path lengthening as possible, thus being useful in cases when networks are jamming due to queuing overload. By using the resulting routing table, a network can sustain significantly higher traffic without jamming than in the case of traditional shortest path routing.Comment: 4 pages, 5 figure

Dozens of virtual impactor orbits eliminated by the EURONEAR VIMP DECam data mining project

Massive data mining of image archives observed with large etendue facilities represents a great opportunity for orbital amelioration of poorly known virtual impactor asteroids (VIs). There are more than 1000 VIs known today; most of them have very short observed arcs and many are considered lost as they became extremely faint soon after discovery. We aim to improve the orbits of VIs and eliminate their status by data mining the existing image archives. Within the European Near Earth Asteroids Research (EURONEAR) project, we developed the Virtual Impactor search using Mega-Precovery (VIMP) software endowed with a very effective (fast and accurate) algorithm to predict apparitions of candidate pairs for subsequent guided human search. Considering a simple geometric model, the VIMP algorithm searches for any possible intersection in space and time between the positional uncertainty of any VI and the bounding sky projection of any image archive. We applied VIMP to mine the data of 451914 Blanco/DECam images observed between 12 Sep 2012 and 11 Jul 2019, identifying 212 VIs that possibly fall into 1286 candidate images leading to either precovery or recovery events. Following a careful search of candidate images, we recovered and measured 54 VIs in 183 DECam images. About 4000 impact orbits were eliminated from both lists, 27 VIs were removed from at least one list, while 14 objects were eliminated from both lists. The faintest detections were around V~24.0, while the majority fall between 21<V<23. The minimal orbital intersection distances remains constant for 67% detections, increasing for eight objects and decreasing for 10 objects. Most eliminated VIs had short initial arcs of less than 5 days. Some unexpected photometric discovery has emerged regarding the rotation period of 2018 DB, based on the close inspection of longer trailed VIs and the measurement of their fluxes along the trails.Comment: Accepted for publication in Astronomy & Astrophysics (27 July 2020

Metal Ir coatings on endocardial electrode tips, obtained by MOCVD

The present work demonstrates the application of the Metal-Organic Chemical Vapor Deposition technique to fabricate metal iridium coatings onto the pole tips of endocardial electrodes. Using iridium (III) acetylacetonate as volatile precursor, the target coatings were successfully applied to the working surface of cathodes and anodes of pacemaker electrodes in the flow type reactor in hydrogen atmosphere at deposition temperature of 550°C. The coating samples were characterized by means of XRD, SEM, Raman- and XPS-spectroscopies. The formation of non-textured coatings with fractal-like morphology and 7-24 nm crystallite size has been realized. The electrochemical properties of the coatings were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The charge storage capacity values of the electrochemically activated samples were 17.0-115 mC·cm–2 and 14.4-76.5 mC·cm–2 for measurements carried out in 0.1M sulfuric acid and in phosphate buffer saline solutions, respectively. A comparison of some characteristics of the samples obtained with commercially available cathode of pacemaker electrodes is also presented

Optimal transport on wireless networks

We present a study of the application of a variant of a recently introduced heuristic algorithm for the optimization of transport routes on complex networks to the problem of finding the optimal routes of communication between nodes on wireless networks. Our algorithm iteratively balances network traffic by minimizing the maximum node betweenness on the network. The variant we consider specifically accounts for the broadcast restrictions imposed by wireless communication by using a different betweenness measure. We compare the performance of our algorithm to two other known algorithms and find that our algorithm achieves the highest transport capacity both for minimum node degree geometric networks, which are directed geometric networks that model wireless communication networks, and for configuration model networks that are uncorrelated scale-free networks.Comment: 5 pages, 4 figure

Regression analysis of properties of [Au(IPr)(CHR2)] complexes

The European Research Council (ERC) and the Engineering and Physical Sciences Research Council (EPSRC), UK, are gratefully acknowledged for their support. L.C., and S.P.N. thank the King Abdullah University of Science and Technology (KAUST) and Kind Saud University (KSU) for support.New [Au(IPr)(CHR2)] complexes have been synthesised through protonolysis reactions of [Au(IPr)(OH)] with moderately acidic substrates, CH2R2. An array of spectroscopic (IR and NMR), structural (X-ray), electronic (DFT) and experimental (reactivity) parameters was collected to quantify the variation in stereoelectronic properties of these new and previously reported [Au(IPr)(CHR2)] complexes. Variation of the R substituents on the carbanion ligands (CHR2–) was found to have a crucial impact on parameters characterising the resulting gold complexes. A regression analysis of both experimental and modelled parameters, guided by network analysis techniques, produced linear models that supported trends within the [Au(IPr)(CHR2)] complexes.PostprintPeer reviewe

Morphological evaluation of fetal membranes and placenta of wild life Mazama gouazoubira deer in the first third of pregnancy

Mazama gouazoubira, o veado-catingueiro, é uma espécie de cervídeo de porte pequeno, que pode ser encontrado na América do Sul, desde o sul do Uruguai até o norte de Mato Grosso, no Brasil. Este estudo teve como objetivo descrever as membranas fetais e a placenta de M. gouazoubira no terço inicial de gestação. As amostras coletadas foram analisadas macroscopicamente e microscopicamente. O exame do útero demonstrou uma gestação univitelina e um embrião com crown-rump de 13mm. Na análise do embrião pode ser observado o olho pigmentado, as saliências auriculares, o mesonefro e e metanefro em desenvolvimento, o fígado e sua proeminência externa, o estômago, os membros torácicos e os brotos dos membros pélvicos. A placenta apresentou-se oligocotiledonária e no útero puderam ser observadas nove carúnculas. O saco gestacional mediu 15cm de comprimento e, como observado no início da gestação dos ruminantes domésticos, os cotilédones não puderam ser identificados macroscopicamente. Uma fraca adesão foi observada entre as carúnculas e a membrana corioalantóica (cotilédones) que formavam os placentônios. A membrana corioalantóica demonstrou um alantóide bem vascularizado composto por uma fina camada de células de núcleos e citoplasmas alongados. Na outra face da membrana, o cório foi composto por células cúbicas, de citoplasmas escassos e núcleos grandes e arredondados, características de células trofoblásticas. Envolvendo o embrião visualizou-se o saco amniótico constituído de duas camadas passíveis de separação mecânica, que apresentaram morfologia similar, sendo formadas por um epitélio pavimentoso avascular. Não foi observado saco vitelino no estágio gestacional do espécime estudado. Conclui-se que a placenta de M. gouazoubira é oligocotiledonária, como observado em outros cervídeos, e que as membranas fetais apresentam semelhanças com a de outros ruminantes, incluindo as características citológicas. Estudos adicionais são necessários para determinar a presença do saco vitelino e quando ocorre sua regressão.Mazama gouazoubira is a small-sized deer, which can be found in South America, from southern Uruguay to the north of Mato Grosso, Brazil. This study aimed to describe the fetal membranes and placenta of M. gouazoubira in the first third of pregnancy. Samples collected were macroscopically and microscopically analyzed. Uterus examination demonstrated univitelinic gestation with an embryo measuring a crown-rump length of 13mm. In the embryo analysis we could identify the pigmented eye, auricular hillocks, mesonephron and early metanephron, liver and its external prominence, stomach, thoracic members and buds of pelvic members. Placenta was oligocotyledonary and nine caruncles were found in the uterus. Gestational sac measured 15cm in length, and, as observed in the early gestation of domestic ruminants, cotyledons could not be identified macroscopically. A weak adhesion was found between caruncles and chorioallantoic membrane (cotyledons) forming the placentomes. The chorioallantoic membrane showed a well-vascularized allantoid composed by a thin layer of cells with stretched nucleus and cytoplasm. On the other side of the membrane, the chorion was composed by cubic cells with scant cytoplasm and large-rounded nuclei, features of trophoblast cells. Involving the embryo we identified a two-layered amniotic sac. Layers could be mechanically separated and had similar morphology, showing a non-vascularized squamous epithelium. There was no yolk sac in the gestational stage of this specimen. We concluded that the placenta of M. gouazoubira is an oligocotyledonary placenta, as observed in others cervids, and that the fetal membranes showed similarities with those from other domestic ruminants, including cytological characteristics. Further studies are required in order to determine the presence of the yolk sac and its regression time

Two-stage Recognition and Beyond for Compound Facial Emotion Recognition

Facial emotion recognition is an inherently complex problem due to individual diversity in facial features and racial and cultural differences. Moreover, facial expressions typically reflect the mixture of people’s emotional statuses, which can be expressed using compound emotions. Compound facial emotion recognition makes the problem even more difficult because the discrimination between dominant and complementary emotions is usually weak. We have created a database that includes 31,250 facial images with different emotions of 115 subjects whose gender distribution is almost uniform to address compound emotion recognition. In addition, we have organized a competition based on the proposed dataset, held at FG workshop 2020. This paper analyzes the winner’s approach—a two-stage recognition method (1st stage, coarse recognition; 2nd stage, fine recognition), which enhances the classification of symmetrical emotion labels

A Microfabricated Segmented-Involute-Foil Regenerator for Enhancing Reliability and Performance of Stirling Engines: Phase II Final Report for the Radioisotope Power Conversion Technology NRA Contract NAS3-03124

An actual-size microfabricated regenerator comprised of a stack of 42 disks, 19 mm diameter and 0.25 mm thick, with layers of microscopic, segmented, involute-shaped flow channels was fabricated and tested. The geometry resembles layers of uniformly-spaced segmented-parallel-plates, except the plates are curved. Each disk was made from electro-plated nickel using the LiGA process. This regenerator had feature sizes close to those required for an actual Stirling engine but the overall regenerator dimensions were sized for the NASA/Sunpower oscillating-flow regenerator test rig. Testing in the oscillating-flow test rig showed the regenerator performed extremely well, significantly better than currently used random-fiber material, producing the highest figures of merit ever recorded for any regenerator tested in that rig over its ~20 years of use

Distributed flow optimization and cascading effects in weighted complex networks

We investigate the effect of a specific edge weighting scheme $\sim (k_i k_j)^{\beta}$ on distributed flow efficiency and robustness to cascading failures in scale-free networks. In particular, we analyze a simple, yet fundamental distributed flow model: current flow in random resistor networks. By the tuning of control parameter $\beta$ and by considering two general cases of relative node processing capabilities as well as the effect of bandwidth, we show the dependence of transport efficiency upon the correlations between the topology and weights. By studying the severity of cascades for different control parameter $\beta$, we find that network resilience to cascading overloads and network throughput is optimal for the same value of $\beta$ over the range of node capacities and available bandwidth