Deep neural networks for network routing

In this work, we propose a Deep Learning (DL) based solution to the problem of routing traffic flows in computer networks. Routing decisions can be made in different ways depending on the desired objective and, based on that objective function, optimal solutions can be computed using a variety of techniques, e.g. with mixed integer linear programming. However, determining these solutions requires solving complex optimization problems and, thus, cannot be typically done at runtime. Instead, heuristics for these problems are often created but designing them is non-trivial in many cases. The routing framework proposed here presents an alternative to the design of heuristics, whilst still achieving good performance. This is done by building a DL model trained on the optimal decisions over flows from known traffic demands. To evaluate our solution, we focused on the problem of network congestion, even though a wide range of alternative objectives could be fitted into this framework. We ran experiments using two publicly available datasets of networks with real traffic demands and showed that our solution achieves close-to-optimal network congestion values.This research was sponsored by the U.S. Army Research Laboratory and the U.K. Ministry of Defence under Agreement Number W911NF-16-3-0001.info:eu-repo/semantics/publishedVersio

The K giant star Arcturus: the hybrid nature of its infrared spectrum

We study infrared spectrum of Arcturus to clarify the nature of the cool component of its atmosphere, referred to as the CO-mosphere, with the use of the IR spectral atlas by Hinkle et al.(1995). The nature of CO lines shows an abrupt change at logW/nu = -4.75, and the lines stronger than this limit can no longer be analyzed by the classical line-formation theory. A more simple manifestation of this fact is that the curves-of-growth (CG) of CO lines show an unpredictable upturn at logW/nu = -4.75. Similar unusual behaviors of empirical CG are confirmed in other red (super)giant stars, and it looks as if the CG is a hybrid of at least two components of different origins. Although strong lines of the CO fundamentals observed in Arcturus show strengthening compared with the predicted photospheric spectrum, the weaker lines show slight weakening, and we interpret these results as due to absorption/emission by the molecular clouds formed in the extended atmosphere. Now do clouds exist in stellar atmospheres? It is by no means easy to answer this question by spectroscopic observations alone, but we find several arguments in favor of such a possibility in Arcturus by analyzing the CO lines. In cooler (super)giant stars in which CO lines show similar unusual behaviors as in Arcturus, the presence of molecular clouds in the outer atmospheres was demonstrated by direct observations with spatial interferometry. We suggest that the formation of molecular clouds is a general feature in cool luminous stars from early K to late M (super)giant stars.Comment: 18 pages, 15 Postscript figures, 1 Table in electronic form, Accepted for publication in Astronomy and Astrophysic

'Dressage Is Full of Queens!' Masculinity, Sexuality and Equestrian Sport

Attitudes towards sexuality are changing and levels of cultural homophobia decreasing, yet there remain very few openly gay men within sport. As a proving ground for heteromasculinity, sport has traditionally been a hostile environment for gay men. This article is based on an ethnographic study within a sporting subworld in which gay men do appear to be accepted: equestrian sport. Drawing on inclusive masculinity theory, equestrian sport is shown to offer an unusually tolerant environment for gay men in which heterosexual men of all ages demonstrate low levels of homophobia. Inclusive masculinity theory is a useful framework for exploring the changing nature of masculinities and this study demonstrates that gay men are becoming increasingly visible and accepted within once unreceptive locales, such as sport and rural communities. However, this more tolerant attitude is purchased at the expense of a subordinated feminine Other, perpetuating the dominance of men within competitive sport. © The Author(s) 2012

Superfluid Bosons and Flux Liquids: Disorder, Thermal Fluctuations, and Finite-Size Effects

The influence of different types of disorder (both uncorrelated and correlated) on the superfluid properties of a weakly interacting or dilute Bose gas, as well as on the corresponding quantities for flux line liquids in high-temperature superconductors at low magnetic fields are reviewed, investigated and compared. We exploit the formal analogy between superfluid bosons and the statistical mechanics of directed lines, and explore the influence of the different "imaginary time" boundary conditions appropriate for a flux line liquid. For superfluids, we discuss the density and momentum correlations, the condensate fraction, and the normal-fluid density as function of temperature for two- and three-dimensional systems subject to a space- and time-dependent random potential as well as conventional point-, line-, and plane-like defects. In the case of vortex liquids subject to point disorder, twin boundaries, screw dislocations, and various configurations of columnar damage tracks, we calculate the corresponding quantities, namely density and tilt correlations, the ``boson'' order parameter, and the tilt modulus. The finite-size corrections due to periodic vs. open "imaginary time" boundary conditions differ in interesting and important ways. Experimental implications for vortex lines are described briefly.Comment: 78 pages, RevTex, 4 figures included (sorry, there are no ps-files for the remaining 2 figures; if needed, please send mail to [email protected]); brief erratum appended (2 pages

Collaborative Gaze Channelling for Improved Cooperation During Robotic Assisted Surgery

The use of multiple robots for performing complex tasks is becoming a common practice for many robot applications. When different operators are involved, effective cooperation with anticipated manoeuvres is important for seamless, synergistic control of all the end-effectors. In this paper, the concept of Collaborative Gaze Channelling (CGC) is presented for improved control of surgical robots for a shared task. Through eye tracking, the fixations of each operator are monitored and presented in a shared surgical workspace. CGC permits remote or physically separated collaborators to share their intention by visualising the eye gaze of their counterparts, and thus recovers, to a certain extent, the information of mutual intent that we rely upon in a vis-à-vis working setting. In this study, the efficiency of surgical manipulation with and without CGC for controlling a pair of bimanual surgical robots is evaluated by analysing the level of coordination of two independent operators. Fitts' law is used to compare the quality of movement with or without CGC. A total of 40 subjects have been recruited for this study and the results show that the proposed CGC framework exhibits significant improvement (p<0.05) on all the motion indices used for quality assessment. This study demonstrates that visual guidance is an implicit yet effective way of communication during collaborative tasks for robotic surgery. Detailed experimental validation results demonstrate the potential clinical value of the proposed CGC framework. © 2012 Biomedical Engineering Society.link_to_subscribed_fulltex

Modeling the evolution of infrared galaxies: A Parametric backwards evolution model

We aim at modeling the infrared galaxy evolution in an as simple as possible way and reproduce statistical properties among which the number counts between 15 microns and 1.1 mm, the luminosity functions, and the redshift distributions. We then aim at using this model to interpret the recent observations (Spitzer, Akari, BLAST, LABOCA, AzTEC, SPT and Herschel), and make predictions for future experiments like CCAT or SPICA. This model uses an evolution in density and luminosity of the luminosity function with two breaks at redshift ~0.9 and 2 and contains the two populations of the Lagache et al. (2004) model: normal and starburst galaxies. We also take into account the effect of the strong lensing of high-redshift sub-millimeter galaxies. It has 13 free parameters and 8 additional calibration parameters. We fit the parameters to the IRAS, Spitzer, Herschel and AzTEC measurements with a Monte-Carlo Markov chain. The model ajusted on deep counts at key wavelengths reproduces the counts from the mid-infrared to the millimeter wavelengths, as well as the mid-infrared luminosity functions. We discuss the contribution to the cosmic infrared background (CIB) and to the infrared luminosity density of the different populations. We also estimate the effect of the lensing on the number counts, and discuss the recent discovery by the South Pole Telescope (SPT) of a very bright population lying at high-redshift. We predict confusion level for future missions using a P(D) formalism, and the Universe opacity to TeV photons due to the CIB.Comment: 25 pages, 10 tables, 18 figures, accepted for publication in A&

Physical structure of the photodissociation regions in NGC 7023: Observations of gas and dust emission with <i>Herschel</i>

The determination of the physical conditions in molecular clouds is a key step towards our understanding of their formation and evolution of associated star formation. We investigate the density, temperature, and column density of both dust and gas in the photodissociation regions (PDRs) located at the interface between the atomic and cold molecular gas of the NGC 7023 reflection nebula. We study how young stars affect the gas and dust in their environment. Our approach combining both dust and gas delivers strong constraints on the physical conditions of the PDRs. We find dense and warm molecular gas of high column density in the PDRs

Dual mechanism of brain injury and novel treatment strategy in maple syrup urine disease

Maple syrup urine disease (MSUD) is an inherited disorder of branched-chain amino acid metabolism presenting with lifethreatening cerebral oedema and dysmyelination in affected individuals. Treatment requires life-long dietary restriction and monitoring of branched-chain amino acids to avoid brain injury. Despite careful management, children commonly suffer metabolic decompensation in the context of catabolic stress associated with non-specific illness. The mechanisms underlying this decompensation and brain injury are poorly understood. Using recently developed mouse models of classic and intermediate maple syrup urine disease, we assessed biochemical, behavioural and neuropathological changes that occurred during encephalopathy in these mice. Here, we show that rapid brain leucine accumulation displaces other essential amino acids resulting in neurotransmitter depletion and disruption of normal brain growth and development. A novel approach of administering norleucine to heterozygous mothers of classic maple syrup urine disease pups reduced branched-chain amino acid accumulation in milk as well as blood and brain of these pups to enhance survival. Similarly, norleucine substantially delayed encephalopathy in intermediate maple syrup urine disease mice placed on a high protein diet that mimics the catabolic stress shown to cause encephalopathy in human maple syrup urine disease. Current findings suggest two converging mechanisms of brain injury in maple syrup urine disease including: (i) neurotransmitter deficiencies and growth restriction associated with branchedchain amino acid accumulation and (ii) energy deprivation through Krebs cycle disruption associated with branched-chain ketoacid accumulation. Both classic and intermediate models appear to be useful to study the mechanism of brain injury and potential treatment strategies for maple syrup urine disease. Norleucine should be further tested as a potential treatment to prevent encephalopathy in children with maple syrup urine disease during catabolic stress

High stakes and low bars: How international recognition shapes the conduct of civil wars

When rebel groups engage incumbent governments in war for control of the state, questions of international recognition arise. International recognition determines which combatants can draw on state assets, receive overt military aid, and borrow as sovereigns—all of which can have profound consequences for the military balance during civil war. How do third-party states and international organizations determine whom to treat as a state's official government during civil war? Data from the sixty-one center-seeking wars initiated from 1945 to 2014 indicate that military victory is not a prerequisite for recognition. Instead, states generally rely on a simple test: control of the capital city. Seizing the capital does not foreshadow military victory. Civil wars often continue for many years after rebels take control and receive recognition. While geopolitical and economic motives outweigh the capital control test in a small number of important cases, combatants appear to anticipate that holding the capital will be sufficient for recognition. This expectation generates perverse incentives. In effect, the international community rewards combatants for capturing or holding, by any means necessary, an area with high concentrations of critical infrastructure and civilians. In the majority of cases where rebels contest the capital, more than half of its infrastructure is damaged or the majority of civilians are displaced (or both), likely fueling long-term state weakness