Search results for " Classification"
showing 10 items of 1043 documents
Influence of Initial Water Content on the Wettability of Autoclaved Soils
2010
Autoclaving is a commonly used practice to destroy microbial activity in soils but is thought to have a limited effect on other soil properties. Small changes in chemical composition have been reported, but there have been no previous reports of any alteration of physical properties. This study, however, showed that autoclaving can cause a major change in soil hydraulic properties. For samples with intermediate water contents (10-35% v/v), it caused severe or extreme water repellency in three of four soil types tested, although no effect for initially low or high water contents was found. These findings have important implications for any experimental work involving soil autoclaving as a pr…
Contrasting evolution of iron phase composition in soils exposed to redox fluctuations
2018
Abstract Ferric iron (FeIII) solid phases serve many functions in soils and sediments, which include providing sorption sites for soil organic matter, nutrients, and pollutants. The reactivity of Fe solid phases depends on the mineral structure, including the overall crystallinity. In redox-active soils and sediments, repeated reductive dissolution with subsequent exposure to aqueous ferrous iron (Fe2+) and oxidative re-precipitation can alter Fe phase crystallinity and reactivity. However, the trajectory of Fe mineral transformation under redox fluctuations is unclear and has been reported to result in both increases and decreases in Fe phase crystallinity. Several factors such as water bu…
Authentication of protected designation of origin artichokes by spectroscopy methods
2016
Abstract Artichoke samples with the protected designation of origin (PDO) ‘Alcachofa de Benicarlo’ were discriminated from those produced in other towns surrounding Valencia and Murcia, outside the PDO frame. Inductively coupled plasma (ICP-OES), near infrared (NIR) and X-ray fluorescence (XRF) were assayed in order to achieve a correct sample classification of the three different origin sample groups (Benicarlo, Valencia and Murcia). Chemometrics was used to compare the ability of classification of artichoke from their origin by using concentration data of mineral elements, determined by ICP-OES, NIR spectra and XRF spectra. Multivariate analysis tools, as principal component analysis (PCA…
A new paradigm for pattern classification: Nearest Border Techniques
2013
Published version of a chapter in the book: AI 2013: Advances in Artificial Intelligence. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-319-03680-9_44 There are many paradigms for pattern classification. As opposed to these, this paper introduces a paradigm that has not been reported in the literature earlier, which we shall refer to as the Nearest Border (NB) paradigm. The philosophy for developing such a NB strategy is as follows: Given the training data set for each class, we shall first attempt to create borders for each individual class. After that, we advocate that testing is accomplished by assigning the test sample to the class whose border it lies closest to…
Recent trends of temperature change under hot and cold desert climates: Comparing the Sahara (Libya) and Central Asia (Xinjiang, China)
2011
Abstract According to trend computations at three stations each in Sahara desert (Libya), characterized by a “hot” desert type (“BWh”, according to the Koeppen climate classification), and in Central Asia (Xinjiang, China) identified as a “cold” desert type (“BWk”, after Koeppen), increasing annual temperatures were detected over the period 1955–2005 corresponding with global temperature warming. From 1955–1978, negative (decreasing) temperature trends were, however, observed at all three hot desert stations and at two of the three cold desert stations. From 1979–2005, strikingly positive temperature trends were seen at all six stations. In seasonal respects, winter (December to February) a…
Climate Classification and Division of China
1988
As far as a climate classification and division is concerned, China represents a great complexity and diversity due to the country’s vast territory and extremely complex landforms. In detail, three major climate-governing factors must be taken into consideration for the climate of China as such and for its division over space: (1) the geographical latitude, (2) the elevation above sea level and (3) the distance from the Pacific Ocean. Of particular importance for a climate regionalization of China is the country’s location on the southeastern corner of the Eurasian continent against the Pacific Ocean, which means that the nature of the surrounding regions varies from open oceans to compact …
The Three Steps of Clustering In The Post-Genomic Era
2013
This chapter descibes the basic algorithmic components that are involved in clustering, with particular attention to classification of microarray data.
Phytoplankton dynamics in permanent and temporary Mediterranean waters: is the game hard to play because of hydrological disturbance?
2012
Only few scientific investigations have been carried out, to our knowledge, on phytoplankton in Mediterranean temporary ponds. To test the hypothesis that climate forcing is the main factor affecting dynamics and structure of planktic algae in these peculiar ecosystems, and to assess the importance of human impacts on this basic component of the aquatic biota, phytoplankton structure and dynamics were analysed in two temporary, long lasting (9 months), ponds, and in a permanent one. The three studied water bodies can be classified as mesoeutrophic, which show extended macrophyte beds and are subjected to one or more human impacts, such as eutrophication, fish and plant introduction, and gar…
Comparison of Metrics for the Classification of Soils Under Variable Geometrical Conditions Using Hyperspectral Data
2008
International audience; The objective of this letter is to find a distance metric between reflectance spectra that is not sensitive to the variations on the soil reflectance induced by the geometry of solar-view angles. This is motivated by the fact that differences between spectra measured for the same soil under different observation and illumination configurations can lead to misclassifications. Using 26 soils of different compositions simulated with Hapke’s model and 92 soils of different compositions measured under 28 solarview angle geometries in laboratory conditions, we tested three metrics, namely, root-mean-square error, spectral angle mapper, and R2 (the coefficient of determinat…