The tail of the maximum of Brownian motion minus a parabola

We analyze the tail behavior of the maximum N of Brownian motion minus a parabola and give an asymptotic expansion for P(N>x) as x tends to infinity. This extends a first order result on the tail behavior, which can be deduced from Huesler and Piterbarg (1999). We also point out the relation between certain results in Groeneboom (2010) and Janson, Louchard and Martin-L\"of (2010).Comment: 12 pages, submitted to the Electronic Communications in Probabilit

Quantifying the rural-urban gradient in Latin America and the Caribbean

This paper addresses the deceptively simple question: What is the rural population of Latin America and the Caribbean (LAC)? It argues that rurality is a gradient, not a dichotomy, and nominates two dimensions to that gradient: population density and remoteness from large metropolitan areas. It uses geographically referenced population data (from the Gridded Population of the World, version 3) to tabulate the distribution of populations in Latin America and in individual countries by population density and by remoteness. It finds that the popular perception of Latin America as a 75 percent urban continent is misleading. Official census criteria, though inconsistent between countries, tend to classify as"urban"small settlements of less than 2,000 people. Many of these settlements are however embedded in an agriculturally based countryside. The paper finds that about 13 percent of Latin America populations live at ultra-low densities of less than 20 per square kilometer. Essentially these people are more than an hour's distance from a large city, and more than half live more than four hours'distance. A quarter of the population of Latin America is estimated to live at densities below 50, again essentially all of them more than an hour's distance from a large city. Almost half (46 pecent) of Latin America live at population densities below 150 (a conventional threshold for urban areas), and more than 90 percent of this group is at least an hour's distance from a city; about one-third of them (18 percent of the total) are more than four hours distance from a large city.Agricultural Research,Demographics,Health Indicators,,Health Information&Communications Technologies

A dynamic model of filament eruptions and two ribbon flares

Two basically different models for the filament equilibrium by Kippenhahn and Schluter (1957) and Kuperus and Raadu (1974) have appeared in the literature. A further analyses by van Tend and Kuperus (1978) added the force due to the horizontal component of the background field to the Kuperus and Raadu model. In order to obtain a better model which actually describes these phenomena, the evolution of the filament has to be considered in detail. A first attempt was recently presented by Kaastra. Kaastra did not formulate the precise energy balance equations for the problem, as is done in the present work. In the present model not only the force balance, but also the energy balance of the filament is taken into account. Thus a fully closed system of equations is obtained, that describes the evolution of the filament, first in force equilibrium during the current build-up phase, then in the non-equilibrium phase before the eruption, and the eruption itself. A neutral point appears above the photospheric surface in the non-equilibrium phase, but long before the eruption. It was found that although the filament itself may be in non-equilibrium, the evolution may still be slow up to the height where the eruption takes place. The eruption of the filament itself causes a large induced electric field at the neutral point which leads to the observed flare phenomena

Andreev reflection from non-centrosymmetric superconductors and Majorana bound state generation in half-metallic ferromagnets

We study Andreev reflection at an interface between a half metal and a superconductor with spin-orbit interaction. While the absence of minority carriers in the half metal makes singlet Andreev reflection impossible, the spin-orbit interaction gives rise to triplet Andreev reflection, i.e., the reflection of a majority electron into a majority hole or vice versa. As an application of our calculation, we consider a thin half metal film or wire laterally attached to a superconducting contact. If the half metal is disorder free, an excitation gap is opened that is proportional to the spin-orbit interaction strength in the superconductor. For electrons with energy below this gap a lateral half-metal--superconductor contact becomes a perfect triplet Andreev reflector. We show that the system supports localized Majorana end states in this limit.Comment: 14 pages, 3 figure

SIW cavity-backed slot (multi-)antenna systems for the next generation IoT applications

Substrate integrated waveguide (SIW) cavity-backed slot antenna topologies are promising candidates to adress the specific design challenges posed by the Internet of Things (IoT). In this contribution, we demonstrate their potential by discussing two designs on two different, application-specific, innovative substrate materials. First, a compact, ultra-wideband three-element array with very low mutual coupling is presented for integration into furniture. In the second design, the half-mode SIW technique is applied to obtain a miniaturized ultra-wideband design, enabling invisible integration into cork floor and wall tiles. The compactness, integrability, and stable, high performance of both designs in different operating conditions, make them ideal candidates for IoT applications

Iridium oxide as actuator material for the ISFET-based sensor-actuator system

Acid or base concentrations can be determined by performing an acid-base titration with Coulometrically generated OH- or H+ ions at a noble-metal actuator electrode in close proximity to the pH-sensitive gate of an ISFET. The ISFET is used as the indicator electrode to detect the equivalence point in the titration curve. The potential of the actuator electrode during the generation of the titrant is relatively high for the anodic water electrolysis (or relatively low for the cathodic reaction). Consequently other redox couples which are possibly present in the sample solution can interfere with the water electrolysis. This reduces the efficiency of the current to titrant generation on which this measurement relies. To overcome this problem, iridium oxide has been used as a new electroactive material for the actuator electrode. The reversible redox reaction in this metal oxide occurs at a favourable potential and is attended by the exclusive uptake or release of protons, making a titration possible. It is shown that a Coulometric titration in the presence of Cl¿ ions, formerly not possible with the noble-metal actuator electrode because of the redox interference, can now successfully be carried out with iridium oxide as the actuator material. Calculations show that the ISFET pH-sensor is well suited to determining accurately the equivalence point in the steep part of the titration curve, because of its short response time

Sustaining a federation of future internet experimental facilities

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Social networking: A matter of character?

Over the last couple of years, online social networks such as Facebook have tremendously grown in popularity, especially among students. The technological advancements proceed faster than the understanding of the psychological factors behind this development. While motivations and gratifications related to Facebook usage have been investigated thoroughly, this study additionally focuses on the influence of underlying personality factors. However, instead of the commonly used Big Five, the characteristics narcissism, shyness and loneliness are investigated among undergraduate and graduate students. The results indicate that a high score on narcissism causes a higher Facebook usage and that the sub construct uniqueness/entitlement is the most important. The results also indicate a negative influence of loneliness on Facebook usage, while shyness seems irrelevant

Monitoring and debugging using an SDK for NFV-powered telecom applications

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