Search results for " Network"

SparseHC: A Memory-efficient Online Hierarchical Clustering Algorithm

2014

Computing a hierarchical clustering of objects from a pairwise distance matrix is an important algorithmic kernel in computational science. Since the storage of this matrix requires quadratic space with respect to the number of objects, the design of memory-efficient approaches is of high importance to this research area. In this paper, we address this problem by presenting a memory-efficient online hierarchical clustering algorithm called SparseHC. SparseHC scans a sorted and possibly sparse distance matrix chunk-by-chunk. Meanwhile, a dendrogram is built by merging cluster pairs as and when the distance between them is determined to be the smallest among all remaining cluster pairs. The k…

Spatial analysis of the Italian seismic network and seismicity

2018

Seismic networks are powerful tools for understanding active tectonic processes in a monitored region. Their numerous applications, from monitoring seismicity to characterizing seismogenic volumes and generated seismicity, make seismic networks essential tools for assessing seismic hazard in active regions. The ability to locate earthquakes hypocenters requires a seismic network with a sufficient number of optimally distributed, stations. It is important to assess existing network geometry, to identify seismogenic volumes that are not adequately monitored, and to quantify measures that will allow network improvement. In this work we have studied the spatial arrangement of the stations of th…

Continuum: A spatiotemporal data model to represent and qualify filiation relationships

2013

International audience; This work introduces an ontology-based spatio-temporal data model to represent entities evolving in space and time. A dynamic phenomenon generates a complex relationship network between the entities involved in the process. At the abstract level, the relationships can be identity or topological filiations. The existence of an identity filiation depends on whether the object changes its identity or not. On the other hand, topological filiations are based exclusively on the spatial component, like in the case of growth, reduction, merging or splitting. When combining identity and topological filiations, six filiation relationships are obtained, forming a second abstrac…

The «villages» of Paris: revealing the organization of geographical areas by aggregating preferential human movements

2013

International audience

SCOPE-Based Emulators for Fast Generation of Synthetic Canopy Reflectance and Sun-Induced Fluorescence Spectra

2017

Progress in advanced radiative transfer models (RTMs) led to an improved understanding of reflectance (R) and sun-induced chlorophyll fluorescence (SIF) emission throughout the leaf and canopy. Among advanced canopy RTMs that have been recently modified to deliver SIF spectral outputs are the energy balance model SCOPE and the 3D models DART and FLIGHT. The downside of these RTMs is that they are computationally expensive, which makes them impractical in routine processing, such as scene generation and retrieval applications. To bypass their computational burden, a computationally effective technique has been proposed by only using a limited number of model runs, called emulation. The idea …

Application of neural networks in diagnostics of chemical compounds based on their infrared spectra

2017

Abstract The paper presents possibilities of using the so-called „finger-print“ identification method and artificial neural network (ANN) for diagnosis of chemical compounds. The construction of a tool specifically developed for this purpose and the ANN, as well as the required conditions for its proper functioning were described. The identification of chemical compounds was tested in two different ways for proving correctness of the assumptions. First of all, initial studies were carried out with the objective to verify the proper functioning of the developed procedure for IR spectrum interpretation. The second research stage was to find out how the properties of artificial neural networks…

Two new organic-selenate salts: syntheses and crystal structures of bis(di-iso-propylammonium) selenate and di-n-butylammonium hydrogenoselenate

2017

Abstract Two new dialkyammonium selenate salts [i-Pr2NH2]2[SeO4] (1) and [n-Bu2NH2][HSeO4] (2) have been isolated and characterized by single-crystal X-ray diffraction. Salt 1 crystallizes in the monoclinic system, space group P21/n with a=8.7190(5), b=8.8500(4), c=22.5953(9) Å, β=94.6290(17)°, V=1737.84(14) Å3 and Z=4. Salt 2 crystallizes in the monoclinic system space group P21/n with a=10.9328(9), b=8.1700(6), c=13.8095(11) Å, β=97.130(3)°, V=1223.94(17) Å3 and Z=4. In both salts, dialkylammonium cations and selenate anions are connected through NH···O and OH···O hydrogen bonds. In the crystal structure, 1 and 2 are organized in layer-like arrangements. Structural characterizations were …

Statistical validation of investment decisions and transactions in financial markets

Elasticity and stiffness evolution in random fibre networks

2003

Aftermarket strategy and business networks : case study of a hydraulic motor firm

2018

The aftermarket is a big potential for any business as it can be more profitable than sales of the primary product. Previous aftermarket studies are focused on a supply chain approach to the aftermarket using pricing and logistics strategies for different types of industrial markets and limited to case studies from the automotive industry. Small to medium sized enterprises such as hydraulic motor companies have gained international markets due to their technological superiority and have reached niche market segments all over the world. This research aimed to create a profitable aftermarket strategy for a hydraulic motor company with an international niche market. The unique challenges of th…