Search results for "component"
showing 10 items of 1682 documents
Unsupervised deep feature extraction of hyperspectral images
2014
This paper presents an effective unsupervised sparse feature learning algorithm to train deep convolutional networks on hyperspectral images. Deep convolutional hierarchical representations are learned and then used for pixel classification. Features in lower layers present less abstract representations of data, while higher layers represent more abstract and complex characteristics. We successfully illustrate the performance of the extracted representations in a challenging AVIRIS hyperspectral image classification problem, compared to standard dimensionality reduction methods like principal component analysis (PCA) and its kernel counterpart (kPCA). The proposed method largely outperforms…
Classification of Plant Ecological Units in Heterogeneous Semi-Steppe Rangelands: Performance Assessment of Four Classification Algorithms.
2021
Plant Ecological Unit’s (PEUs) are the abstraction of vegetation communities that occur on a site which similarly respond to management actions and natural disturbances. Identification and monitoring of PEUs in a heterogeneous landscape is the most difficult task in medium resolution satellite images datasets. The main objective of this study is to compare pixel-based classification versus object-based classification for accurately classifying PEUs with four selected different algorithms across heterogeneous rangelands in Central Zagros, Iran. We used images of Landsat-8 OLI that were pan-sharpened to 15 m to classify four PEU classes based on a random dataset collected in the field (40%). …
Identification and quantification of meat product ingredients by whole-genome metagenomics (All-Food-Seq)
2019
AbstractComplex food matrices bear the risk of intentional or accidental admixture of non-declared species. Moreover, declared components can be present in false proportions, since expensive taxa might be exchanged for cheaper ones. We have previously reported that PCR-free metagenomic sequencing of total DNA extracted from sausage samples combined with bioinformatic analysis (termed All-Food-Seq, AFS), can be a valuable screening tool to identify the taxon composition of food ingredients. Here we illustrate this principle by analysing regional Doner kebap samples, which revealed unexpected and unlabelled poultry and plant components in three of five cases. In addition, we systematically ap…
Phytochemical Profile and Antioxidant Activity of the Aerial Part Extracts from Matthiola incana subsp. rupestris and subsp. pulchella (Brassicaceae)…
2021
As part of a project aimed at investigating the Matthiola taxa endemic to Sicily (Italy), this study focused on Matthiola incana, an edible species used in the traditional medicine of various countries. Herein, the characterization of phenolic and volatile compounds, the antioxidant capacity in vitro (1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe2+ chelating activity assays) and the toxicity test (Artemia salina lethality bioassay) of the hydroalcoholic extracts from the aerial parts of M. incana subsp. rupestris from Mt. Pellegrino (Palermo) and Mt. Erice (Trapani), and of M. incana subsp. pulchella are reported. The results are compared with those previously shown for M. inc…
Contribution to a Taxonomic Revision of the Sicilian Helichrysum Taxa by PCA Analysis of Their Essential-Oil Compositions
2016
The chemical profile of the essential oils in ten populations of the genus Helichrysum Mill. (Asteraceae), collected in the loci classici of the nomenclatural types of the taxa endemic to Sicily, were analyzed. Our results confirm that the analysis of secondary metabolites can be used to fingerprint wild populations of Helichrysum, the chemical profiles being coherent with the systematic arrangement of the investigated populations in three main clusters, referring to the aggregates of H. stoechas, H. rupestre, and H. italicum, all belonging to the section Stoechadina. The correct nomenclatural designation of the investigated populations is discussed and the following two new combinations ar…
Chemical Composition of the Essential Oil of Mentha pulegium Growing Wild in Sicily and its Activity on Microorganisms Affecting Historical Art Crafts
2017
The chemical composition of the essential oil from aerial parts of Mentha pulegium L. (Linné) collected in Sicily was evaluated by GC and GC-MS. The main components were pulegone (50.6%), piperitenone (27.8%) and menthone (6.9%). Comparison of this oil with other studied oils of different populations is discussed. The oil showed good antibacterial and antifungal activities against some microorganisms that infest historical art works.
Usability of Programming Languages
2016
Programming languages form the interface between programmers (the users) and the computation that they desire the computer to execute. Although studies exist for some aspects of programming language design (such as conditionals), other aspects have received little or no human factors evaluations. Designers thus have little they can rely on if they want to make new languages highly usable, and users cannot easily chose a language based on usability criteria. This SIG will bring together researchers and practitioners interested in increasing the depth and breadth of studies on the usability of programming languages, and ultimately in improving the usability of future languages. nonPeerReviewed
Usability challenges in digital learning solutions
2015
Usability is a key element in successful software. Ensuring the technical usability of a learning solution enables users to focus on their main task, learning. The purpose of this paper is to demonstrate the results of heuristic usability evaluations of digital learning solutions. Heuristic evaluations were conducted on 24 digital learning solutions from one country (Finland) and two country groups (Asian countries and Spanish speaking countries) concentrating on the usability of the user interface of each evaluated solution. The main results of this study indicate that a few heuristics cover the majority of all usability problems (UPs) observed in learning solutions, but these heuristics c…
Drawback of ICA Procedure on EEG: Polarity Indeterminacy at Local Optimization
2008
Independent component analysis (ICA) has been extensively applied to reject artifacts in electroencephalography (EEG) signal processing. The first step is to extract the independent component activations from the electrode records, and then project the desired components back to the electrodes. After the composition of the projected component is analyzed in details under ICA procedure, this study shows that since ICA may extract some source components at the local optimization in high-dimensional EEG signal space, the artificial polarity indeterminacy may happen on the projected component at some electrodes. By numerical simulations, this issue also exhibits that this polarity ambiguity occ…
Molecular Clustering of Phenylurea Herbicides: Comparison with Sulphonylureas, Pesticides and Persistent Organic Pollutants
2014
Chromatographic retention times of phenylurea herbicides are modelled by structure–property relationships. Properties are hydration free energy and dipole. Bioplastic evolution is an evolutionary perspective conjugating the effect of acquired characters and relations that emerge among evolutionary indeterminacy, morphological determination and natural selection principles. Classification algorithms are proposed based on information entropy and production. Phenylureas are classified by Cl2, O2 and N2 presence; their different behaviour depends on the number of Cl atoms. When applying procedures to moderate-sized sets, excessive results appear compatible with data and suffer a combinatorial e…