Search results for "Spatial"

Spatial conflicts betweem modernizations of railway lines and natural values A case study of Poznań - Szczecin railway line

2017

One of the most intensive processes in the development of Polish transport infrastructure is currently modernizing main national railway lines. One of them is the railway line between Poznan and Szczecin. During the realization of such projects there occur conflicts in fulfilling different ecosystem functions by landscapes. On the basis of the theory of ecosystem services these conflicts should be solved, and potential projects – optimized. The study evaluates natural values of the areas adjacent to the railway line Poznań - Szczecin within a zone of 250 m, and also identifies areas with varying conflict degrees for the realization of the modernization project. The most important areas of h…

Determinants of the interannual relationships between remote sensed photosynthetic activity and rainfall in tropical Africa

2007

International audience; The response of photosynthetic activity to interannual rainfall variations in Africa South of the Sahara is examined using 20 years (1981-2000) of Normalised Difference Vegetation Index (NDVI) AVHRR data. Linear correlations and regressions were computed between annual NDVI and annual rainfall at a 0.5° latitude/longitude resolution, based on two gridded precipitation datasets (Climate Prediction Center Merged Analysis of Precipitation [CMAP] and Climatic Research Unit [CRU]). The spatial patterns were then examined to detect how they relate to the mean annual rainfall amounts, land-cover types as from the Global Land Cover 2000 data set, soil properties and soil typ…

Disrupted Spatial Organization of Cued Exogenous Attention Persists Into Adulthood in Developmental Dyslexia

2021

Purpose: Abnormal exogenous attention orienting and diffused spatial distribution of attention have been associated with reading impairment in children with developmental dyslexia. However, studies in adults have failed to replicate such relationships. The goal of the present study was to address this issue by assessing exogenous visual attention and its peripheral spatial distribution in adults with developmental dyslexia.Methods: We measured response times, accuracy and eye movements of 18 dyslexics and 19 typical readers in a cued discrimination paradigm, in which stimuli were presented at different peripheral eccentricities.Results: Results showed that adults with developmental dyslexia…

Teritorijas, resursi un plānošana. Telpiskā plānošana un attīstība: programma un tēzes (2012.g. 2.-3.februāris; Rīga, Alberta iela 10)

2012

Confidence maps: a tool to evaluate archaeological data's relevance in spatial analysis

2007

L'article est disponible en ligne sur Virtual Library Propylaeum : http://archiv.ub.uni-heidelberg.de/propylaeumdok/volltexte/2010/551/pdf/08_05_ostir_et_al_confidence.pdf; International audience

Fundamentals of Precision Agriculture

2023

Precision agriculture or precision farming is the targeted application of crop input according to the locally determined crop needs. Therefore, it is the geo-referenced application of crop inputs, whose rates should be those required by the crop. The most essential points of information about the topic being described are: overview; brief history of precision agriculture; theoretical basics of precision agriculture; precision agriculture cycle; geo-referenced measurement of within-field parameters; analysis and interpretation of geo-referenced data for mapping within-field parameters; spatially variable rate application of crop inputs; instruments for precision agriculture; current scenario…

Data from: Learning outdoors: Male lizards show flexible spatial learning under semi-natural conditions

2013

Spatial cognition is predicted to be a fundamental component of fitness in many lizard species, and yet some studies suggest that it is relatively slow and inflexible. However, such claims are based on work conducted using experimental designs or in artificial contexts that may underestimate their cognitive abilities. We used a biologically realistic experimental procedure (using simulated predatory attacks) to study spatial learning and its flexibility in the lizard Eulamprus quoyii in semi-natural outdoor enclosures under similar conditions to those experienced by lizards in the wild. To evaluate the flexibility of spatial learning, we conducted a reversal spatial-learning task in which p…

Spatial source phase : A new feature for identifying spatial differences based on complex-valued resting-state fMRI data

2019

Spatial source phase, the phase information of spatial maps extracted from functional magnetic resonance imaging (fMRI) data by data‐driven methods such as independent component analysis (ICA), has rarely been studied. While the observed phase has been shown to convey unique brain information, the role of spatial source phase in representing the intrinsic activity of the brain is yet not clear. This study explores the spatial source phase for identifying spatial differences between patients with schizophrenia (SZs) and healthy controls (HCs) using complex‐valued resting‐state fMRI data from 82 individuals. ICA is first applied to preprocess fMRI data, and post‐ICA phase de‐ambiguity and den…

Road network characterization to understand city evolution

2021

International audience; Cities combine different kind of processes that drive their evolution. It is of a great interest to understand the effects of different kinds of spatial patterns on those processes, to be able to minimize space consumption and optimize mobility and transportation.In this research, we aim to contribute to the understanding of city evolution by a focus on the road network of the Eastern French city of Dijon’s. Firstly, we select three network indicators that can be used to characterize the city structure as it grows. We apply these indicators to Dijon’s historical road networks from 1650 until 2019. Finally, we discuss how we can use computational simulations of city g…

Robustifying principal component analysis with spatial sign vectors

2012

In this paper, we apply orthogonally equivariant spatial sign covariance matrices as well as their affine equivariant counterparts in principal component analysis. The influence functions and asymptotic covariance matrices of eigenvectors based on robust covariance estimators are derived in order to compare the robustness and efficiency properties. We show in particular that the estimators that use pairwise differences of the observed data have very good efficiency properties, providing practical robust alternatives to classical sample covariance matrix based methods. peerReviewed