Search results for "Decomposition"
showing 10 items of 766 documents
Exacus: Efficient and Exact Algorithms for Curves and Surfaces
2005
We present the first release of the Exacus C++ libraries. We aim for systematic support of non-linear geometry in software libraries. Our goals are efficiency, correctness, completeness, clarity of the design, modularity, flexibility, and ease of use. We present the generic design and structure of the libraries, which currently compute arrangements of curves and curve segments of low algebraic degree, and boolean operations on polygons bounded by such segments.
Measuring High-Order Interactions in Rhythmic Processes Through Multivariate Spectral Information Decomposition
2021
Many complex systems in physics, biology and engineering are modeled as dynamical networks and described using multivariate time series analysis. Recent developments have shown that the emergent dynamics of a network system are significantly affected by interactions involving multiple network nodes which cannot be described using pairwise links. While these higher-order interactions can be probed using information-theoretic measures, a rigorous framework to describe them in the frequency domain is still lacking. This work presents an approach for the spectral decomposition of multivariate information measures, capable of identifying higher-order synergistic and redundant interactions betwee…
Dynamic Community Detection for Brain Functional Networks during Music Listening with Block Component Analysis
2023
Publisher Copyright: Author The human brain can be described as a complex network of functional connections between distinct regions, referred to as the brain functional network. Recent studies show that the functional network is a dynamic process and its community structure evolves with time during continuous task performance. Consequently, it is important for the understanding of the human brain to develop dynamic community detection techniques for such time-varying functional networks. Here, we propose a temporal clustering framework based on a set of network generative models and surprisingly it can be linked to Block Component Analysis to detect and track the latent community structure…
A branch-and-price framework for decomposing graphs into relaxed cliques
2021
We study the family of problems of partitioning and covering a graph into/with a minimum number of relaxed cliques. Relaxed cliques are subsets of vertices of a graph for which a clique-defining property—for example, the degree of the vertices, the distance between the vertices, the density of the edges, or the connectivity between the vertices—is relaxed. These graph partitioning and covering problems have important applications in many areas such as social network analysis, biology, and disease-spread prevention. We propose a unified framework based on branch-and-price techniques to compute optimal decompositions. For this purpose, new, effective pricing algorithms are developed, and new…
Degradation of stone materials in the archaeological context of the Greek-Roman Theatre in Taormina (Sicily, Italy)
2010
In the present work results on the degradation phenomena of stone materials in the Ancient Theatre of Taormina, one of the most important Greek–Roman monuments of Sicily, are reported. Artificial stone materials in different conservation conditions were investigated. Samples of salt efflorescences from brick walls and degraded setting mortars were taken from the open gallery in “summa cavea”. The chemical, physical and structural characterization was performed by means of X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF), both in situ and ex situ. Results showed that the deterioration of stone materials is due to the aggressive action of the enviro…
Pressure-induced chemical decomposition of copper orthovanadate (α-Cu3V2O8)
2021
The high pressure stability of α-Cu3V2O8 has been investigated via complementary high pressure synchrotron X-ray diffraction experiments and theoretical density functional theory calculations. The results of both experiment and theory are in close agreement. The main result of this work is that α-Cu3V2O8 undergoes a pressure-induced chemical decomposition into CuO and V2O5 at a modest pressure of ∼1.35 GPa according to the experimental observations, and at ∼2.45 GPa according to the calculations. The decomposition is investigated with enthalpy calculations and one of the main driving factors is the stability of the octhedral oxygen-coordination of the metal atoms in the decompositon product…
Investigation of sterols as potential biomarkers for the detection of pig (S. s. domesticus) decomposition fluid in soils
2012
This study was carried out to evaluate the potential of using cholesterol and coprostanol, as indicators for the detection of decomposition fluid of buried pigs (S. s. domesticus) in soils. In May 2007, four pig carcasses (~35. kg) were buried in shallow graves (~40. cm depth) at the University of Ontario Institute of Technology in Canada. Two pigs were exhumed after three months (Pig 1, Pig 2) and six months (Pig 3, Pig 4) post burial. Soil samples were collected beneath the pig carcasses (~40. cm depth) and from grave walls (~15-20. cm depth) as well as from a parallel control site. Coprostanol and cholesterol were extracted from soils, purified with solid phase extraction (SPE) and analy…
Synthesis, Characterization, Thermal and Antimicrobial studies of N-substituted Sulfanilamide derivatives
2014
Abstract Four sulfanilamide derivatives N -[4-(phenylsulfamoyl)phenyl]acetamide (1), 4-amino- N -phenylbenzenesulfonamide (2), N -[4-(phenylsulfamoyl)phenyl]benzamide (3) and N -{4-[(3-chlorophenyl)sulfamoyl]phenylbenzamide (4) were synthesized and characterized by Infra-Red (IR), Nuclear Magnetic Resonance (NMR) and UV–visible (UV–Vis) spectra. Also Liquid Chromatographic (LCMS) and High Resolution Mass Spectrometric (HRMS) methods were used. Crystal structures of 1–4 were determined by single crystal X-ray diffraction (XRD) and their conformational and hydrogen bond (HB) network properties were examined with survey of the literature data. Compounds 1 and 2 crystallize in the same orthorho…
Boundary elements analysis of adhesively bonded piezoelectric active repair
2009
Abstract This paper presents the analysis of active piezoelectric patches for cracked structures by the boundary element method. A two-dimensional boundary integral formulation based on the multidomain technique is used to model cracks and to assemble the multi-layered piezoelectric patches to the host damaged structures. The fracture mechanics behavior of the repaired structures is analyzed for both perfect and imperfect interface between patches and host beams. The imperfect interface, representing the adhesive between two different layers, is modeled by using a “spring model” that involves linear relationships between the interface tractions, in normal and tangential directions, and the …
Photocatalytic Properties of Cement-Based Plasters and Paints Containing Mineral Pigments
2010
Innovative cement-based premix products for surface coating of buildings that possess photocatalytic activity arouse great interest because of the results they can achieve in reducting air pollution and maintaining aesthetics. This photoactivity is induced by a photocatalyst, titanium dioxide, that can accelerate the oxidation processes of air pollutants, particularly nitrogen oxides and volatile organic compounds, which are mainly produced by incomplete combustion of fuel and are present in urban environments through the exhaust gases of motor vehicles. Surfaces that are coated with these products acquire a self-cleaning characteristic (maintenance of original color) because the decomposi…