670 research outputs found
The application of numerical debris flow modelling for the generation of physical vulnerability curves
For a quantitative assessment of debris flow risk, it is essential to consider not only the hazardous process itself but also to perform an analysis of its consequences. This should include the estimation of the expected monetary losses as the product of the hazard with a given magnitude and the vulnerability of the elements exposed. A quantifiable integrated approach of both hazard and vulnerability is becoming a required practice in risk reduction management. This study aims at developing physical vulnerability curves for debris flows through the use of a dynamic run-out model. Dynamic run-out models for debris flows are able to calculate physical outputs (extension, depths, velocities, impact pressures) and to determine the zones where the elements at risk could suffer an impact. These results can then be applied to consequence analyses and risk calculations. On 13 July 2008, after more than two days of intense rainfall, several debris and mud flows were released in the central part of the Valtellina Valley (Lombardy Region, Northern Italy). One of the largest debris flows events occurred in a village called Selvetta. The debris flow event was reconstructed after extensive field work and interviews with local inhabitants and civil protection teams. The Selvetta event was modelled with the FLO-2D program, an Eulerian formulation with a finite differences numerical scheme that requires the specification of an input hydrograph. The internal stresses are isotropic and the basal shear stresses are calculated using a quadratic model. The behaviour and run-out of the flow was reconstructed. The significance of calculated values of the flow depth, velocity, and pressure were investigated in terms of the resulting damage to the affected buildings. The physical damage was quantified for each affected structure within the context of physical vulnerability, which was calculated as the ratio between the monetary loss and the reconstruction value. Three different empirical vulnerability curves were obtained, which are functions of debris flow depth, impact pressure, and kinematic viscosity, respectively. A quantitative approach to estimate the vulnerability of an exposed element to a debris flow which can be independent of the temporal occurrence of the hazard event is presented
Дискурсивно-структурні особливості англомовних текстів описів товарів комерційних інтернет-сайтів
Статтю присвячено визначенню та вивченню дискурсивних та структурних особливостей англомовних текстів описів товарів, розміщених на комерційних сайтах. У дослідженні виділяються основні композиційні елементи та комунікативні блоки структури цього типу текстів, дається характеристика основних паралігвістичних засобів, які у них зустрічаються. Значну увагу також приділено аналізу дейктичних елементів у семантичній структурі електронного тексту.Статья посвящена определению и исследованию дискурсивных и структурных особенностей англоязычных текстов описаний товара, размещенных на коммерческих сайтах. В исследовании выделяются основные композиционные элементы и коммуникативные блоки структуры этого типа текстов, дается характеристика основных паралингвистических средств, встречающихся в них. Значительное внимание также уделено анализу дейктических элементов в семантической структуре электронного текста.The article deals with discursive and structural features of English-language text descriptions of commodity placed on commercial sites. Focus is made on the basic components and communicative blocks of such kinds of texts. The deictic elements in the structure of hypertext are analysed
Dynamic effect of phase conjugation on wave localization
We investigate what would happen to the time dependence of a pulse reflected
by a disordered single-mode waveguide, if it is closed at one end not by an
ordinary mirror but by a phase-conjugating mirror. We find that the waveguide
acts like a virtual cavity with resonance frequency equal to the working
frequency omega_0 of the phase-conjugating mirror. The decay in time of the
average power spectrum of the reflected pulse is delayed for frequencies near
omega_0. In the presence of localization the resonance width is
tau_s^{-1}exp(-L/l), with L the length of the waveguide, l the mean free path,
and tau_s the scattering time. Inside this frequency range the decay of the
average power spectrum is delayed up to times t simeq tau_s exp(L/l).Comment: 10 pages including 2 figure
Dynamics of localization in a waveguide
This is a review of the dynamics of wave propagation through a disordered
N-mode waveguide in the localized regime. The basic quantities considered are
the Wigner-Smith and single-mode delay times, plus the time-dependent power
spectrum of a reflected pulse. The long-time dynamics is dominated by resonant
transmission over length scales much larger than the localization length. The
corresponding distribution of the Wigner-Smith delay times is the Laguerre
ensemble of random-matrix theory. In the power spectrum the resonances show up
as a 1/t^2 tail after N^2 scattering times. In the distribution of single-mode
delay times the resonances introduce a dynamic coherent backscattering effect,
that provides a way to distinguish localization from absorption.Comment: 18 pages including 8 figures; minor correction
Heroes and villains of world history across cultures
© 2015 Hanke et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedEmergent properties of global political culture were examined using data from the World History Survey (WHS) involving 6,902 university students in 37 countries evaluating 40 figures from world history. Multidimensional scaling and factor analysis techniques found only limited forms of universality in evaluations across Western, Catholic/Orthodox, Muslim, and Asian country clusters. The highest consensus across cultures involved scientific innovators, with Einstein having the most positive evaluation overall. Peaceful humanitarians like Mother Theresa and Gandhi followed. There was much less cross-cultural consistency in the evaluation of negative figures, led by Hitler, Osama bin Laden, and Saddam Hussein. After more traditional empirical methods (e.g., factor analysis) failed to identify meaningful cross-cultural patterns, Latent Profile Analysis (LPA) was used to identify four global representational profiles: Secular and Religious Idealists were overwhelmingly prevalent in Christian countries, and Political Realists were common in Muslim and Asian countries. We discuss possible consequences and interpretations of these different representational profiles.This research was supported by grant RG016-P-10 from the Chiang Ching-Kuo Foundation for International Scholarly Exchange (http://www.cckf.org.tw/).
Religion
Culture
Entropy
China
Democracy
Economic histor
Wild olive seed weevil, Anchonocranus oleae Marshall (Coleoptera: Curculionidae), in cultivated olives in South Africa
Wild olive seed weevil, Anchonocranus oleae Marshall, larvae as well as oviposition and feeding damage were recorded in cultivated olives during a recent study on olive seed wasps in South Africa. Prematurely dropped fruit and fruit picked at harvest in two orchards near Stellenbosch and Agter- Paarl were examined regularly for olive seed wasp infestation over three seasons. In addition, olives were collected over a wider area of the olive growing regions of the Western Cape province for a survey to determine olive seed wasp distribution. DNA barcoding confirmed the identity of weevil larvae in kernels as A. oleae. The number of A. oleae larvae found in olive seeds and the number of olives with weevil oviposition or feeding damage were low. The presence of larvae and weevil damage in two orchards in the survey with no wild olive trees in close proximity suggest that the weevil could breed and persist in cultivated olive orchards. Currently A. oleae is not of economic concern, but if infested olives are discarded at harvest and left in orchards, the weevils could complete their development in the kernels and numbers could increase to damaging levels
Radio Emission in Atmospheric Air Showers: First Measurements with LOPES-30
When Ultra High Energy Cosmic Rays interact with particles in the Earth's
atmosphere, they produce a shower of secondary particles propagating toward the
ground. LOPES-30 is an absolutely calibrated array of 30 dipole antennas
investigating the radio emission from these showers in detail and clarifying if
the technique is useful for largescale applications. LOPES-30 is co-located and
measures in coincidence with the air shower experiment KASCADE-Grande. Status
of LOPES-30 and first measurements are presented.Comment: Proceedings of ARENA 06, June 2006, University of Northumbria, U
Wisdom of groups promotes cooperation in evolutionary social dilemmas
Whether or not to change strategy depends not only on the personal success of
each individual, but also on the success of others. Using this as motivation,
we study the evolution of cooperation in games that describe social dilemmas,
where the propensity to adopt a different strategy depends both on individual
fitness as well as on the strategies of neighbors. Regardless of whether the
evolutionary process is governed by pairwise or group interactions, we show
that plugging into the "wisdom of groups" strongly promotes cooperative
behavior. The more the wider knowledge is taken into account the more the
evolution of defectors is impaired. We explain this by revealing a dynamically
decelerated invasion process, by means of which interfaces separating different
domains remain smooth and defectors therefore become unable to efficiently
invade cooperators. This in turn invigorates spatial reciprocity and
establishes decentralized decision making as very beneficial for resolving
social dilemmas.Comment: 8 two-column pages, 7 figures; accepted for publication in Scientific
Report
Perceptions of parents on satisfaction with care in the pediatric intensive care unit: the EMPATHIC study
Abstract:
PURPOSE: To identify parental perceptions on pediatric intensive care-related satisfaction items within the framework of developing a Dutch pediatric intensive care unit (PICU) satisfaction instrument.
METHODS: Prospective cohort study in tertiary PICUs at seven university medical centers in The Netherlands.
PARTICIPANTS: Parents of 1,042 children discharged from a PICU.
RESULTS: A 78-item questionnaire was sent to 1,042 parents and completed by 559 (54%). Seventeen satisfaction items were rated with mean scores or =1.65, and thus considered of limited value. The empirical structure of the items was in agreement with the theoretically formulated domains: Information, Care a
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
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