Search results for " mining"

Geochemical fingerprints of brannerite (UTi 2 O 6 ): an integrated study

2020

AbstractBrannerite (UTi2O6) is among the major uranium-bearing minerals found in ore deposits, however as it has been long considered as a refractory mineral for leaching it is currently disregarded in ore deposits. Brannerite is found in a variety of geological environments with the most common occurrences being hydrothermal and pegmatitic. On the basis of scanning electron microscopy observations coupled with electron probe micro-analyses and laser ablation inductively-coupled plasma mass spectrometer analyses, this study describes the morphological features and the major- and trace-element abundances of brannerite samples from five hydrothermal and five pegmatitic localities across the w…

Towards a Great Design of Conceptual Modelling

2020

Humankind faces a most crucial mission; we must endeavour, on a global scale, to restore and improve our natural and social environments. This is a big challenge for global information systems development and for their modelling. In this paper, we discuss on different aspects of conceptual modelling in global environmental context. The paper is the summary of the panel session “The Future of Conceptual Modelling” in the 29th International Conference on Information Modelling and Knowledge Bases. peerReviewed

ProcMiner: Advancing Process Analysis and Management

2007

This paper contributes both to research and practice on process mining. Previous research on process mining has focused on mining patterns from event log files to generate process models. The process mining approach adopted in this paper is focused on producing patterns about process models, not the models themselves. The approach is demonstrated by ProcMiner -an explorative research prototype for management, consolidating, publishing, retrieving, and analyzing process models. Content-based document clustering is applied to process models represented as XML database in order to find topical groups from models. In practice, organizations face numerous challenges in managing their process mod…

Unstable feature relevance in classification tasks

2011

Knowledge discovery using diffusion maps

2013

3D MODELING OF TWO LOUTERIA FRAGMENTS BY IMAGE-BASED APPROACH

2017

Abstract. The paper presents a digital approach to the reconstruction and analysis of two small-sized fragments of louteria, a kind of large terracotta vase, found during an archaeological survey in the south of Sicily (Italy), in the area of Cignana near the Greek colony of Akragas (nowadays Agrigento). The fragments of louteria have been studied by an image-based approach in order to achieve high accurate and very detailed 3D models. The 3D models have been used to carry out interpretive and geometric analysis from an archaeological point of view. Using different digital tools, it was possible to highlight some fine details of the louteria decorations and to better understand the characte…

CLUSTERING INCOMPLETE SPECTRAL DATA WITH ROBUST METHODS

2018

Abstract. Missing value imputation is a common approach for preprocessing incomplete data sets. In case of data clustering, imputation methods may cause unexpected bias because they may change the underlying structure of the data. In order to avoid prior imputation of missing values the computational operations must be projected on the available data values. In this paper, we apply a robust nan-K-spatmed algorithm to the clustering problem on hyperspectral image data. Robust statistics, such as multivariate medians, are more insensitive to outliers than classical statistics relying on the Gaussian assumptions. They are, however, computationally more intractable due to the lack of closed-for…

Enabling Searches on Wavelengths in a Hyperspectral Indices Database

2018

Abstract. Spectral indices derived from hyperspectral reflectance measurements are powerful tools to estimate physical parameters in a non-destructive and precise way for several fields of applications, among others vegetation health analysis, coastal and deep water constituents, geology, and atmosphere composition. In the last years, several micro-hyperspectral sensors have appeared, with both full-frame and push-broom acquisition technologies, while in the near future several hyperspectral spaceborne missions are planned to be launched. This is fostering the use of hyperspectral data in basic and applied research causing a large number of spectral indices to be defined and used in various…

Advancing stem cells: New therapeutic strategies for treating central nervous system disorders

2018

In this special issue, we explore new methods and knowledge to improve stem cell transplantation in diseases and conditions such as stroke, PD, and depression. Advancing the conventional idea regarding cell replacement in stem cell therapy, stem cells may also transfer healthy mitochondria to diseased ischemic neurons in stroke and improve the therapeutic time window of tissue plasminogen activator (tPA) in a conjunctive therapy for stroke, and human Wharton’s Jelly-derived mesenchymal stromal cells (hWJ-MSCs) may rely mainly on trophic factor secretion to induce neuroprotective effects. In addition, trophic factors such as neurotrophin-4/5 (NT-4/5) and glial cell line-derived neurotrophic …

Effects of hydrogen-charging on the properties of S235JR steel

2017

The paper presents the test results of the S235JR steel susceptibility to damage under the influence of hydrogen. The test of mechanical properties was performed on the basis of a static stretch test of non-hydrogenated samples and after cathodic polarization. Electrochemical measurements for the assessment of corrosion resistance of non-hydrogenated and hydrogenated steels were carried out using open circuit potential measurement and registering of potentiodynamic polarization curves in a three-electrode measuring system. Hydrogenation was carried out for between 3 and 24 hours in a solution of 0.1 N sulfuric acid (VI) with the addition of 2 mg/dm 3 of arsenic oxide (III) at an electric cu…