Search results for " Classification"
showing 10 items of 1043 documents
A trait-based analysis of cover crop strategies for resource acquisition and use: application to weed control in banana cropping systems
2014
International audience
A trait-based method to choose cover plants the best adapted to a cropping system
2014
International audience
Multitemporal Unmixing of Medium-Spatial-Resolution Satellite Images: A Case Study Using MERIS Images for Land-Cover Mapping
2011
Data from current medium-spatial-resolution imaging spectroradiometers are used for land-cover mapping and land-cover change detection at regional to global scales. However, few landscapes are homogeneous at these scales, and this creates the so-called mixed-pixel problem. In this context, this study explores the use of the linear spectral mixture model to extract subpixel land-cover composition from medium-spatial-resolution data. In particular, a time series of MEdium Resolution Imaging Spectrometer (MERIS) full-resolution (FR; pixel size of 300 m) images acquired over The Netherlands is used to illustrate this study. The Netherlands was selected because of the following: 1) the fragmenta…
Spatio-Temporal Effects of Land Use Change on the Anthropogenic Soils Diffusion: A Case Study in a Mediterranean Vineyard Area
2008
Anthropogenic soils created ex novo by land-use change in large scale farming are, from a pedogenetic point of view, catastrophic events that bring the soils to time zero and change the natural pattern of the soilscape, remarkably, in some cases. The quantitative aspects of pedodiversity of a soilscape in South-East Sicily, where some types of soils, in recent decades, have suffered a consistent reduction due to the transformations by large scale farming, are considered. The evolution of pedodiversity over a 53-year period (1955 to 2008) is examined using a dedicated statistical method and a space–time model based on Markov analysis and cellular automata in order to predict the evolution of…
An SVM Ensamble Approach to Detect Irony and Stereotype Spreaders on Twitter
2022
The problem we address in this work is classifying whether a Twitter user has spread Irony and Stereotype or not. We used a text vectorization layer to generate Bag-Of-Words sequences. Then such sequences are passed to three different text classifiers (Decision Tree, Convolutional Neural Network, Naive Bayes). Our final classifier is an SVM. To test and validate our approach we used the dataset provided for the author profiling task organized by PAN@CLEF 2022. Our team (missino) submitted the predictions on the provided test set to participate at the shared task. Over several cross fold validation our approach was able to reach a maximum binary accuracy on the best validation split equal to…
Nozīmes veidošana attēlos: lingvistiskā un paralingvistiskā perspektīva
2021
Darba mērķis ir izpētīt, kā attēlu nozīmi iespējams interpretēt noteiktā kontekstā. Pētījums reaģē uz galējās interpretācijas problemātiku un ierosina skatīt Čārlza Pīrsa zīmju teoriju kā instrumentu, kas ļauj analizēt nozīmes radīšanas un interpretācijas procesualitāti noteiktas situācijas un kultūras kontekstā. Tiek pētīti četri atšķirīgi attēlu gadījumi (Hilma af Klinta, Sajs Tvomblijs, Gerhards Rihters un Vija Celmiņa), piemērojot mainīgos konteksta lielumus un Pīrsa zīmju klasifikācijas. Vijas Celmiņas intervijas fonētiskā un runātā diskursa analīze liecina, ka mākslinieces runātais teksts var attīstīt uztvērēja priekšzinās…
Search for intermediate mass black hole binaries in the first and second observing runs of the Advanced LIGO and Virgo network
2019
Gravitational wave astronomy has been firmly established with the detection of gravitational waves from the merger of ten stellar mass binary black holes and a neutron star binary. This paper reports on the all-sky search for gravitational waves from intermediate mass black hole binaries in the first and second observing runs of the Advanced LIGO and Virgo network. The search uses three independent algorithms: two based on matched filtering of the data with waveform templates of gravitational wave signals from compact binaries, and a third, model-independent algorithm that employs no signal model for the incoming signal. No intermediate mass black hole binary event was detected in this sear…
All-sky search in early O3 LIGO data for continuous gravitational-wave signals from unknown neutron stars in binary systems
2021
Rapidly spinning neutron stars are promising sources of continuous gravitational waves. Detecting such a signal would allow probing of the physical properties of matter under extreme conditions. A significant fraction of the known pulsar population belongs to binary systems. Searching for unknown neutron stars in binary systems requires specialized algorithms to address unknown orbital frequency modulations. We present a search for continuous gravitational waves emitted by neutron stars in binary systems in early data from the third observing run of the Advanced LIGO and Advanced Virgo detectors using the semicoherent, GPU-accelerated, binaryskyhough pipeline. The search analyzes the most s…
A globally relevant stock of soil nitrogen in the Yedoma permafrost domain
2022
AbstractNitrogen regulates multiple aspects of the permafrost climate feedback, including plant growth, organic matter decomposition, and the production of the potent greenhouse gas nitrous oxide. Despite its importance, current estimates of permafrost nitrogen are highly uncertain. Here, we compiled a dataset of >2000 samples to quantify nitrogen stocks in the Yedoma domain, a region with organic-rich permafrost that contains ~25% of all permafrost carbon. We estimate that the Yedoma domain contains 41.2 gigatons of nitrogen down to ~20 metre for the deepest unit, which increases the previous estimate for the entire permafrost zone by ~46%. Approximately 90% of this nitrogen (37 gigaton…
Authentication of the protected designation of origin horchata de Valencia through the chemometric treatment of mineral content
2010
Spanish horchata de chufa samples were authenticated based on the determination of mineral elements by inductively coupled plasma atomic emission spectrometry (ICP-OES) combined with different chemometric methods. The ability of multivariate analysis, such as principle components analysis (PCA), classification and regression trees (CARTs) and discriminant analysis (DA) were evaluated in order to achieve a correct sample classification. It was possible to clearly differentiate homemade and long-life commercial samples by all three methods and CART and DA provided an excellent tool to establish the growth origin of the tiger nuts. CART analysis employed the concentration of Mg to discriminate…