Search results for "principal"
showing 10 items of 795 documents
Explicit signal to noise ratio in reproducing kernel Hilbert spaces
2011
This paper introduces a nonlinear feature extraction method based on kernels for remote sensing data analysis. The proposed approach is based on the minimum noise fraction (MNF) transform, which maximizes the signal variance while also minimizing the estimated noise variance. We here propose an alternative kernel MNF (KMNF) in which the noise is explicitly estimated in the reproducing kernel Hilbert space. This enables KMNF dealing with non-linear relations between the noise and the signal features jointly. Results show that the proposed KMNF provides the most noise-free features when confronted with PCA, MNF, KPCA, and the previous version of KMNF. Extracted features with the explicit KMNF…
Cross-Talk Correction Method for Knee Kinematics in Gait Analysis Using Principal Component Analysis (PCA): A New Proposal
2014
International audience; Background: In 3D gait analysis, the knee joint is usually described by the Eulerian way. It consists in breaking down the motion between the articulating bones of the knee into three rotations around three axes: flexion/extension, abduction/adduction and internal/external rotation. However, the definition of these axes is prone to error, such as the "cross-talk'' effect, due to difficult positioning of anatomical landmarks. This paper proposes a correction method, principal component analysis (PCA), based on an objective kinematic criterion for standardization, in order to improve knee joint kinematic analysis. Methods: The method was applied to the 3D gait data of …
The Role of Agency Theory and Perceived Goal Divergence in IS Continuance: A Replication and Extension Study
2016
Past literature recognizes the power of the well-established information systems continuance theory (ISCT) to explain information systems (IS) continuance. In this study, we integrate constructs from two additional perspectives and discuss their interdependencies with ISCT. We argue that the promising framework proposed by Sorebo et al. [1], which extends ISCT with self-determination theory (SDT), can increase its managerial relevance by adding the variables of users' perceptions of goal divergence and risk aversion, selected from agency theory. The empirical results support Sorebo et al.'s main findings and strongly support the impact of perceived goal divergence on e-learning continuance …
Decoding the dynamics of value cocreation in consumer tribes. An Agency Theory approach
2017
In the last decade, marketing studies have tried to define methodologies, models, and tools to support organizations in developing pathways “oriented to” and “based on” the value cocreation. To shed light on these dynamics, using the interpretative lens offered by Agency Theory, this study investigates the sociocultural and cognitive/figurative roots of the process of emergence of consumer tribes in which and by which value cocreation takes place. This paper offers a possible advancement in knowledge useful to define approaches, models, and instruments able to better explain and manage the dynamics of value cocreation.
ChemInform Abstract: Chemometrics: An Important Tool for the Modern Chemist, an Example from Wood-Processing Chemistry.
2010
This study briefly outlines the idea of principal component analysis and cross-correlation calculations (applied chemometrics) and presents an illustrative example from wood-processing chemistry. The applicability of chemometric data analysis was demonstrated by investigating the various structural changes that take place in dissolved and degraded lignin ("kraft lignin") during laboratory-scale kraft pulping of Scots pine (Pinus sylvestris) and silver birch (Betula pendula). The structural data (31P NMR and size exclusion chromatographic data) on kraft lignin were further processed by chemometric multivariate techniques (PCA and 2DCC), confirming, for example, that the cleavage of beta-aryl…
Chemometrics: An Important Tool for the Modern Chemist, an Example from Wood-Processing Chemistry
2000
This study briefly outlines the idea of principal component analysis and cross-correlation calculations (applied chemometrics) and presents an illustrative example from wood-processing chemistry. The applicability of chemometric data analysis was demonstrated by investigating the various structural changes that take place in dissolved and degraded lignin ("kraft lignin") during laboratory-scale kraft pulping of Scots pine (Pinus sylvestris) and silver birch (Betula pendula). The structural data (31P NMR and size exclusion chromatographic data) on kraft lignin were further processed by chemometric multivariate techniques (PCA and 2DCC), confirming, for example, that the cleavage of beta-aryl…
Chemometric investigation on structural changes in pine kraft lignin during pulping
2000
Abstract Various structural changes which take place in dissolved lignin during the laboratory-scale kraft pulping of Scots pine (Pinus sylvestris) were studied. Lignin samples were subjected to the alkaline cupric oxide oxidation and the analytical data further processed by various multivariate chemometric techniques (principal component analysis, PCA; principal component regression, PCR; and projection to latent structures, PLS). Several models applicable to the indirect measurement of common pine kraft pulp properties (i.e., total cooking yield, kappa number and ISO brightness) were produced.
Implementare le politiche sanitarie a livello regionale per l'eliminazione dell'epatite C ai tempi del COVID-19
2022
Viral hepatitis C is an important public health problem and its elimination by 2030, defined by the World Health Organization, is an ambitious goal. The chance of free screening for HCV infection represents an important achievement that requires a successful State-Regions coordination and an effective regional organisation, that guarantees an interdisciplinary course between local and specialized healthcare. A structured communication program to increase the sensitivity of target populations as well as health professionals is the key for success. The implementation of the proactive screening, defined by the Milleproroghe Law, is crucial because it will define the tracks for the whole HCV co…
Regional frequency analysis of extreme rainfall in Sicily (Italy)
2018
Extreme rainfall events have large impacts on society and are likely to increase in intensity under climate change. For design and management decisions, particularly regarding hydraulic works, accurate estimates of precipitation magnitudes are needed at different durations. In this article, an objective approach of the regional frequency analysis (RFA) has been applied to precipitation data for the island of Sicily, Italy. Annual maximum series for rainfall with durations of 1, 3, 6, 12, and 24 h from about 130 rain gauges were used. The RFA has been implemented using principal component analysis (PCA) followed by a clustering analysis, through the k-means algorithm, to identify statistical…
Les principales mesures des lois de finances
2017
International audience; La loi de finances pour 2017 et la loi de finances rectificative pour 2016 comportent de nombreuses dispositions relatives à la fiscalité des entreprises et des particuliers. Le présent commentaire n’est en rien exhaustif et vise seulement à alerter les lecteurs sur de nouvelles dispositions qui apparaissent les plus notables pour la profession notariale.