90 research outputs found
Differentiable MadNIS-Lite
No full textDifferentiable programming opens exciting new avenues in particle physics, also affecting future event generators. These new techniques boost the performance of current and planned MadGraph implementations. Combining phase-space mappings with a set of very small learnable flow elements, MADNIS-Lite, can improve the sampling efficiency while being physically interpretable. This defines a third sampling strategy, complementing VEGAS and the full MADNIS
The MadNIS reloaded
No full textIn pursuit of precise and fast theory predictions for the LHC, we present an implementation of the MADNIS method in the MADGRAPH event generator. A series of improvements in MADNIS further enhance its efficiency and speed. We validate this implementation for realistic partonic processes and find significant gains from using modern machine learning in event generators
Inferring causal relations from multivariate time series : a fast method for large-scale gene expression data
No full textVarious multivariate time series analysis techniques have been developed with the aim of inferring causal relations between time series. Previously, these techniques have proved their effectiveness on economic and neurophysiological data, which normally consist of hundreds of samples. However, in their applications to gene regulatory inference, the small sample size of gene expression time series poses an obstacle. In this paper, we describe some of the most commonly used multivariate inference techniques and show the potential challenge related to gene expression analysis. In response, we propose a directed partial correlation (DPC) algorithm as an efficient and effective solution to causal/regulatory relations inference on small sample gene expression data. Comparative evaluations on the existing techniques and the proposed method are presented. To draw reliable conclusions, a comprehensive benchmarking on data sets of various setups is essential. Three experiments are designed to assess these methods in a coherent manner. Detailed analysis of experimental results not only reveals good accuracy of the proposed DPC method in large-scale prediction, but also gives much insight into all methods under evaluation
Impact of environmental inputs on reverse-engineering approach to network structures
No full textBackground: Uncovering complex network structures from a biological system is one of the main topic in system biology. The network structures can be inferred by the dynamical Bayesian network or Granger causality, but neither techniques have seriously taken into account the impact of environmental inputs.
Results: With considerations of natural rhythmic dynamics of biological data, we propose a system biology approach to reveal the impact of environmental inputs on network structures. We first represent the environmental inputs by a harmonic oscillator and combine them with Granger causality to identify environmental inputs and then uncover the causal network structures. We also generalize it to multiple harmonic oscillators to represent various exogenous influences. This system approach is extensively tested with toy models and successfully applied to a real biological network of microarray data of the flowering genes of the model plant Arabidopsis Thaliana. The aim is to identify those genes that are directly affected by the presence of the sunlight and uncover the interactive network structures associating with flowering metabolism.
Conclusion: We demonstrate that environmental inputs are crucial for correctly inferring network structures. Harmonic causal method is proved to be a powerful technique to detect environment inputs and uncover network structures, especially when the biological data exhibit periodic oscillations
Evolution in Archaeology
No full textThis review begins with a brief outline of the key concepts of Darwinian archaeology. Its history is then summarized, beginning with its emergence as a significant theoretical focus within the discipline in the early 1980s; its main present-day currents are then presented, citing examples of recent work. The developments in archaeology are part of broader trends in anthropology and psychology and are characterized by the same theoretical disagreements. There are two distinct research traditions: one centered on cultural transmission and dual inheritance theory and the other on human behavioral ecology. The development of specifically archaeological methodologies within these two traditions for testing evolutionary hypotheses relating to diachronic questions using archaeological data is discussed. Finally, this review suggests that the greatest challenge for the future lies in finding ways of using archaeological data to address current major debates in evolutionary social science as a whole concerning, for example, the emergence of largescale cooperation
Estudo da viabilidade de revitalização de curso d'agua em área urbana: estudo de caso no Rio Córrego Grande em Florianópolis, Santa Catarina
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro TecnológicoAs atuais circunstâncias de degradação ambiental presente nos centros urbanos são em sua maioria originadas pela ação antrópica. Estas situações são representadas por fatores tais como, poluição atmosférica, poluição sonora e visual, desmatamento as florestas, degradação do solo e corpos hídricos. Com a percepção da importância em tratar das conseqüências da deterioração da integridade física dos cursos d'água, como por exemplo, os problemas relacionados às inundações e a poluição das águas, a presente pesquisa vem a tratar desta temática. Fazem parte da integridade física dos cursos d'água elementos como, hidrologia, a geomorfologia, a qualidade da água e a biodiversidade aquática e no seu entorno. O estado em que se encontram estes elementos pode ser analisado pela observação de fatores, tais como, degradação da mata ciliar; lançamento de efluentes e resíduos sólidos no leito e nas margens do curso d'água; retificação da seção transversal do curso d'água e corte de meandros e a ocupação urbana na faixa de preservação permanente. A presente pesquisa tem por objetivo avaliar a degradação ambiental em um curso d'água, visando a definição medidas de revitalização em situação consolidada de ocupação urbana na zona de proteção legal deste curso d'água, por intermédio de um estudo de caso. Para tanto, são empregadas metodologias de avaliação de impactos ambientais (AIA), como check-list e matrizes de interação. A aplicação de tais metodologias aos diferentes trechos do rio Córrego Grande mostra-se eficiente para caracterizar a degradação de um curso d'água no meio urbano, podendo resultar na proposição de medidas de revitalização adequadas e realistas. The current circumstances of the environmental degradation presented in urban areas are mostly caused by human action. These situations are represented by factors such as air pollution, noise and visual pollution, deforestation of forests, soil and water degradation. Noticed the urgency to treat the consequences of the deterioration of the physical integrity of water courses, such as the problems related to flooding and to water pollution, this research is related to this thematic. Elements such as hydrology, geomorphology, water quality and aquatic and its surroundings biodiversity make part of the physical integrity of water courses. The situation of these elements can be analyzed by the observation of some factors, such as "riparian forest" degradation; effluents and solid waste discharge in the bed and banks of water course; rectification of the cross section of the course water and cutting of "meanders" and urban occupation in the range of permanent preservation. This study aims to assess the environmental degradation in a water course, aimed at defining measures to revitalise a consolidated situation of occupation in the urban area of legal protection of the water course, through a case study. For both, are employed methodologies for assessing environmental impacts as check-list and matrices of interaction. The application of such methodologies for different stretches of the river Córrego Grande shows to be efficient to characterize the degradation of a course in urban water and may result in proposals for measures to revitalise appropriate and realistic
O dever jurídico de restauração ambiental: percepção da natureza como projeto
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Jurídicas. Programa de Pós-Graduação em Direito.A presente Dissertação tem como enfoque central a verificação da forma pela qual a implementação das técnicas de restauração ambiental pode contribuir para a preservação da biodiversidade, mediante a aplicação da técnica mais condizente com o dever constitucional de restauração dos processos ecológicos essenciais, trazido pela Constituição Federal de 1988 e recepcionado pela legislação infraconstitucional. Como contexto, traz a reflexão acerca da relação paradigmática existente entre homem e natureza. Tal relação sugere, por um lado, a apropriação desta por ele e, de outro, a atribuição de seus próprios direitos. Sugere-se, ao longo do texto, a substituição dessas posturas antagônicas pela percepção das complexidades que perpassam tal relação. É analisada, também, a recepção jurídica do meio ambiente e da restauração ambiental. Além disso, a complexidade é discutida, principalmente, quanto ao bem ambiental e aos contornos traçados pelo dano ambiental, tanto na sua avaliação, quanto na sua reparação. Essa é analisada nas três esferas de responsabilidade do sistema jurídico brasileiro: civil, administrativa e penal, tendo em vista o dever de restauração. Na tentativa de superação das contradições que permeiam a restauração ambiental, propõe-se a abordagem transdisciplinar do tema, concretizado por meio do diálogo do saber jurídico com o ecológico. A partir desse estudo, são constatados alguns parâmetros ecológicos a serem seguidos na implementação da restauração. Suas observações vão ser demonstradas como cruciais para a distinção entre os processos de restauração e recuperação ambiental e para a busca da preservação da biodiversidade. Como resultado, são evidenciadas as principais características das técnicas nucleadoras de restauração ambiental, analisadas com relação à observação dos fenômenos presentes na natureza e tomadas como condizentes com o dever de restauração dos processos ecológicos essenciais
How Predictable are Temperature-series Undergoing Noise-controlled Dynamics in the Mediterranean
No full textMediterranean is thought to be sensitive to global climate change, but its future interdecadal variability is uncertain for many climate models. A study was made of the variability of the winter temperature over the Mediterranean Sub-regional Area (MSA), employing a reconstructed temperature series covering the period 1698 to 2010. This paper describes the transformed winter temperature data performed via Empirical Mode Decomposition for the purposes of noise reduction and statistical modeling. This emerging approach is discussed to account for the internal dependence structure of natural climate variability
Estimation of stem attributes using a combination of terrestrial and airborne laser scanning
No full textProperties of individual trees can be estimated from airborne laser scanning (ALS) data provided that the scanning is dense enough and the positions of field-measured trees are available as training data. However, such detailed manual field measurements are laborious. This paper presents new methods to use terrestrial laser scanning (TLS) for automatic measurements of tree stems and to further link these ground measurements to ALS data analyzed at the single tree level. The methods have been validated in six 80 × 80 m field plots in spruce-dominated forest (lat. 58°N, long. 13°E). In a first step, individual tree stems were automatically detected from TLS data. The root mean square error (RMSE) for DBH was 38.0 mm (13.1 %), and the bias was 1.6 mm (0.5 %). In a second step, trees detected from the TLS data were automatically co-registered and linked with the corresponding trees detected from the ALS data. In a third step, tree level regression models were created for stem attributes derived from the TLS data using independent variables derived from trees detected from the ALS data. Leave-one-out cross-validation for one field plot at a time provided an RMSE for tree level ALS estimates trained with TLS data of 46.0 mm (15.4 %) for DBH, 9.4 dm (3.7 %) for tree height, and 197.4 dm3 (34.0 %) for stem volume, which was nearly as accurate as when data from manual field inventory were used for training
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