Ardelio Galletti

Ardelio Galletti
Parthenope University of Naples | Università Parthenope · Department of Science and Technology

Ph.D. in Applied Mathematics (Numerical Analysis)

About

73
Publications
7,417
Reads
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858
Citations
Citations since 2016
49 Research Items
798 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
Additional affiliations
May 2008 - April 2016
Parthenope University of Naples
Position
  • Professor (Assistant)
May 2008 - April 2016
Parthenope University of Naples
Position
  • Professor (Assistant)
October 2006 - April 2008
University of Naples Federico II
Position
  • Temporary Research Associate

Publications

Publications (73)
Article
Full-text available
Gaussian convolution operation is a fundamental procedure in several data analysis tasks and scientific fields. For example, Gaussian convolution is a central step in data assimilation and machine learning and it is also frequently used in image and signal processing. Gaussian recursive filters are a class of methods designed to approximate Gaussia...
Chapter
In recent years, Machine Learning (ML) algorithms have proved to be very helpful in several research fields, such as engineering, health-science, physics etc. Among these fields, Astrophysics also started to develop a stronger need of ML techniques for the management of big-data collected by ongoing and future all-sky surveys (e.g. Gaia, LAMOST, LS...
Article
Data Assimilation process is generally used to estimate the best initial state of a system in order to predict carefully the future states. This powerful technique has been widely applied in investigations of the atmosphere, ocean, and land surface. In this work, we deal with the Gaussian convolution operation which is a central step of the Data As...
Article
In the current work, an efficient and powerful computational technique is implemented to simulate an anomalous mobile-immobile solute transport process. The process is mathematically modelled as a time-fractional mobile-immobile diffusion equation in the sense of Riemann-Liouville derivative. Firstly, an implicit time integration procedure is used...
Chapter
Machine Learning algorithms try to provide an adequate forecast for predicting and understanding a multitude of phenomena. However, due to the chaotic nature of real systems, it is very difficult to predict data: a small perturbation from initial state can generate serious errors. Data Assimilation is used to estimate the best initial state of a sy...
Article
Full-text available
While the everything as a sensor is a typical data gathering pattern in the Internet of Things (IoT) applications in contexts such as smart cities, smart factories, and precision agriculture, among others, the use of the same technique in the coastal marine environment is still not explored at full potential. Nevertheless, when it comes to maritime...
Chapter
In this work we deal with the solution of a two-dimensional inverse time fractional diffusion equation, involving a Caputo fractional derivative in his expression. Since we deal with a huge practical problem with a large domain, by starting from an accurate meshless localized collocation method using RBFs, here we propose a fast algorithm, implemen...
Article
Data from sensors incorporated into mobile devices, such as networked navigational sensors, can be used to capture detailed environmental information. We describe here a workflow and framework for using sensors on boats to construct unique new datasets of underwater topography (bathymetry). Starting with a large number of measurements of position,...
Article
Full-text available
In this work, we describe and implement a data assimilation approach for PM10 pollution data in Northern Italy. This was done by combining the best available information from observations and chemical transport models. Specifically, by (1) incorporating PM10 surface daily concentrations and model results from the CAMS (Copernicus Atmosphere Monitor...
Article
Fast technology development has influenced the widespread use of low‐power devices in different scientific, environmental, and everyday life areas, giving birth to the Internet of Things. In this paper, we focus on the context of marine studies, addressing the problem of marine bathymetry data processing and analysis via pervasive and Internet‐conn...
Conference Paper
It is well known that the standard formulation of the Smoothed Particle Hydrodynamics is usually poor when scattered data distribution is considered or when the approximation near the boundary occurs. Moreover, the method is computational demanding when a high number of data sites and evaluation points are employed. In this paper an enhanced versio...
Chapter
Full-text available
Data crowdsourcing is one of most remarkable results of pervasive and internet connected low-power devices making diverse and different “things” as a world wide distributed system. This paper is focused on a vertical application of GPGPU virtualization software exploitation targeted on high performance geographical data interpolation. We present an...
Article
Full-text available
Data reduction algorithms often produce inaccurate results for loss of relevant information. Recently, the singular value decomposition (SVD) method has been used as preprocessing method in order to deal with high-dimensional data and achieve fuzzy-rough reduct convergence on higher dimensional datasets. Despite the well-known fact that SVD offers...
Conference Paper
Recursive Filters (RFs) are a well-known way to approximate the Gaussian convolution and, due to their computational efficiency, are intensively used in several technical and scientific fields. The accuracy of the RFs can be improved by means of the repeated application of the filter, which gives rise to the so-called K-iterated Gaussian recursive...
Article
Recently, advanced computing systems are widely adopted in order to intensively elaborate a huge amount of biomedical data in the e-health field. An interesting challenge is to perform real-time diagnosis by means of complex computational environments. In this paper, we suggest to deal the most computationally expensive processing steps of a distri...
Article
Full-text available
Nowadays fishes and mussels farming is very important, from an economical point of view, for the local social background of the Bay of Naples. Hence, the accurate forecast of marine pollution becomes crucial to have reliable evaluation of its adverse effects on coastal inhabitants’ health. The use of connected smart devices for monitoring the sea w...
Conference Paper
Sensors incorporated into mobile devices provide unique opportunities to capture detailed environmental information that cannot be readily collected in other ways. We show here how data from networked navigational sensors on leisure vessels can be used to construct unique new datasets, using the example of underwater topography (bathymetry) to demo...
Conference Paper
Full-text available
Generic Virtualization Service (GVirtuS) is a new solution for enabling GPGPU on Virtual Machines or low powered devices. This paper focuses on the performance analysis that can be obtained using a GPGPU virtualized software. Recently, GVirtuS has been extended in order to support CUDA ancillary libraries with good results. Here, our aim is to anal...
Article
In many applications, the Gaussian convolution is approximately computed by means of recursive filters, with a significant improvement of computational efficiency. We are interested in theoretical and numerical issues related to such an use of recursive filters in a three-dimensional variational data assimilation (3Dvar) scheme as it appears in the...
Article
In this paper, we propose a fine-to-coarse parallelization strategy in order to exploit, in a case study, a parallel hybrid architecture. We consider the Optical Flow numerical problem, modelled by partial differential equations, and implement a parallel multilevel software. Our hybrid software solution is a smart combination between codes on Graph...
Article
In this paper, starting from a comprehensive mathematical model of a Collaborative Reputation Systems (CRSes), we present a research study within the Cultural Heritage domain. The main goal of this study has been the evaluation and classification of the visitors’ behaviour during a cultural event. By means of mobile technological instruments, oppor...
Article
Data for which ratios of parts are more important than absolute values have a compositional nature and should be analysed in the (D - 1)-dimensional simplex, but in order to use standard multivariate analysis techniques they are often mapped bijectively from the simplex into the ordinary Euclidean space. The additive log-ratio (alr) is one popular...
Article
Full-text available
The extraction of information from IoT data plays a fundamental role in many fields. In this paper we focus our attention on financial data and we use them to describe derivatives in the Black-Scholes model. This model lets us obtain an expression of the price of a derivative in a complete market with no possibility of arbitrage portfolios. Traders...
Article
Full-text available
Nowadays, in the Internet of Things (IoT) society, the massive use of technological devices available to the people makes possible to collect a lot of data describing tastes, choices and behaviours related to the users of services and tools. These information can be rearranged and interpreted in order to obtain a rating (i.e., evaluation) of the su...
Article
Full-text available
Among the many challenges that the Internet of Things poses, the accuracy of the sensor network and relative data flow is of the foremost importance: sensors monitor the surrounding environment of an object and give information on its position, situation or context, and an error in the acquired data can lead to inappropriate decisions and uncontrol...
Article
Representation of curves and surfaces is a basic topic in computer graphic and computer aided design (CAD). In this paper we focus on theoretical and practical issues in using radial basis functions (RBF) for reconstructing implicit curves and surfaces from point clouds. We study the conditioning of the problem and give some insight on how the prob...
Conference Paper
The algorithms based on the Bregman iterative regularization are known for efficiently solving convex constraint optimization problems. In this paper, we introduce a second order derivative scheme for the class of Bregman algorithms. Its properties of convergence and stability are investigated by means of numerical evidences. Moreover, we apply the...
Conference Paper
Recursive filters (RFs) have achieved a central role in several research fields over the last few years. For example, they are used in image processing, in data assimilation and in electrocardiogram denoising. More in particular, among RFs, the Gaussian RFs are an efficient computational tool for approximating Gaussian-based convolutions and are su...
Chapter
The implementation of neural network models enables to reproduce complex biological phenomena. The tuning of a large number of biological parameters and synaptic mechanisms of several different cells that belong to a model is a very critical issue. In this work, we present the effects of increasing cAMP Response Element Binding protein (CREB)-depen...
Conference Paper
We focus on the Overcomplete Local Principal Component Analysis (OLPCA) method, which is widely considered as the state-of-the-art denoising filter. We propose a programming approaches resorting to massively parallel architectures, known as Graphic Processor Units (GPUs), in order to deal with the heavy computational complexity of the algorithm. In...
Conference Paper
An interesting challenge in e-Health is to develop tools and software in order to benefit the healthcare services. Our applicative context is Magnetic Resonance Imaging (MRI). The main purpose of this paper is to propose a regularization framework for solving an inverse reconstruction problem in MRI. We focus on the Split Bregman method, which is a...
Conference Paper
Full-text available
We focus on the Overcomplete Local Principal Component Analysis (OLPCA) method, which is widely adopted as denoising filter. We propose a programming approach resorting to Graphic Processor Units (GPUs), in order to massively parallelize some heavy computational tasks of the method. In our approach, we design and implement a parallel version of the...
Conference Paper
Full-text available
In the last decade, algorithms for reputation systems are been widely developed in order to achieve correct ratings for products, services, companies, digital contents and people. We start from a comprehensive mathematical model for Collaborative Reputation Systems (CRSes), present in the literature and formally defined as a recurrence relation tha...
Chapter
Full-text available
A smart system for a cultural exhibition, generally, has the ability to infer interests of users and to track the propagation of the information into the event. We are interested in analysing and studying the visiting styles of users in a real cultural heritage exhibition, named The Beauty or the Truth. Starting from data that was collected during...
Article
Full-text available
In many healthcare applications, artifacts mask or corrupt important features of Electrocardiogram (ECG) signals. In this paper we describe a revised scheme for ECG signal denoising based on a recursive filtering methodology. We suggest a suitable class of kernel functions in order to remove artifacts in the ECG signal, starting from noise frequenc...
Conference Paper
In recent years, the real-time diagnosis in the E-health is widely used practice. Employing distributed computing systems, it is possible to obtain excellent results, avoiding long delays and invasive processes. However, the data processing stage, generally assigned on standard computational CPU environments, is a critical aspect, especially when t...
Chapter
Full-text available
Classify the dynamic of users in a cultural heritage exhibition in order to infer information about the event fruition is a very interesting research field. In this paper, starting from real data, we investigate the user dynamics related to the interaction with artworks and how a spectator interacts with available technologies. Accordingly with the...
Conference Paper
Classify the dynamic of users in a cultural heritage exhibition in order to infer information about the event fruition is a very interesting research field. In this paper, starting from real data, we investigate the user dynamics related to the interaction with artworks and how a spectator interacts with available technologies. Accordingly with the...
Article
Full-text available
In this work we present a multi-level parallel framework for the Optical Flow computation on a GPUs cluster, equipped with a scientific computing middleware (the PetSc library). Starting from a flow-driven isotropic method, which models the optical flow problem through a parabolic partial differential equation (PDE), we have designed a parallel alg...
Article
Full-text available
The prototyping and the development of computational codes for biological models, in terms of reliability, efficient and portable building blocks allow to simulate real cerebral behaviours and to validate theories and experiments. A critical issue is the tuning of a model by means of several numerical simulations with the aim to reproduce real scen...
Article
Full-text available
High quality Electrocardiogram (ECG) data is very important because this signal is generally used for the analysis of heart diseases. Wearable sensors are widely adopted for physical activity monitoring and for the provision of healthcare services, but noise always degrades the quality of these signals. This paper describes a new algorithm for ECG...
Conference Paper
Full-text available
In this paper, starting from a real case of an art exhibit, we propose a mathematical model to simulate social network interactions of a visitor that shares his experience on a social network. The Integrate & Fire (I&F) model is used to reproduce the interest of spectators in a cultural heritage community. In our approach, visitor is modelled as a...
Conference Paper
An interesting challenge in E-health is to perform real-time diagnosis. In many distributed computing systems the data processing stage, generally assigned on standard computational CPU environments, is a critical aspect. In particular, the analysis of magnetic resonance imaging (MRI) for improving the quality of images and helping the diagnosis re...
Conference Paper
Full-text available
Wearable sensors are widely adopted for the provision of healthcare services. Unfortunately the noise always degrades the quality of the acquired signals. In this paper, we propose a framework for mobile ECG denoising, based on a novel numerical scheme with low computational requirements. The proposed system is able to store a signal from a wearabl...
Article
Piecewise interpolation methods, as spline or Hermite cubic interpolation methods, define the interpolating function by means of polynomial pieces and ensure that some regularity conditions hold at the break-points. In this paper, starting from a previous work, where we proposed a class of piecewise interpolating functions whose expression depends...
Chapter
Full-text available
Many problems in computer visualization, scientific computing, medical imag- ing, computer-aided design and manufacturing (CAD/CAM) require to recon- struct a graphic object starting from an unorganized 2D/3D point cloud, i.e. a set of scattered points in R^2 or R^3. Here, we – establish how the problem parameters and the results have to be taken i...
Conference Paper
In this paper, a biologically inspired mathematical model to simulate social network behaviours is presented. We propose a computational network of Integrate & Fire (IF) neurons to model the dynamics of spectators in a community that shares interests on cultural heritage assets. In our approach, users are assimilated to neurons, while the friendshi...
Article
Piecewise interpolation methods, as spline or Hermite cubic interpolation methods, define the interpolant function by means of polynomial pieces and ensure that some regularity conditions are guaranteed at the break-points. In this work, we propose a novel class of piecewise interpolating functions whose expression depends on the barycentric coordi...
Article
Full-text available
Computational kernel of the three-dimensional variational data assimilation (3D-Var) problem is a linear system, generally solved by means of an iterative method. The most costly part of each iterative step is a matrix-vector product with a very large covariance matrix having Gaussian correlation structure. This operation may be interpreted as a Ga...
Article
Local numerical methods for scattered data interpolation often require a smart subdivision of the domain in geometrical polyhedral structures. In particular triangulations in the plane (2D) and tetrahedrizations in the space (3D) are widely used to define interpolation models. In this paper we give a short survey on the main methods for the scatter...
Article
This paper concerns the connection between Mathematics and Music. After a description of the nature of sound, the problem of the construction of the musical scale, from the studies of Pythagoras to the tempered scale is considered. An algorithm for the construction of a scale is given. © 2014 Salvatore Cuomo, Ardelio Galletti and Gabriele Guerriero...
Article
Full-text available
In this paper we describe a parallel implicit method based on radial basis functions (RBF) for surface reconstruction. The applicability of RBF methods is hindered by its computational demand, that requires the solution of linear systems of size equal to the number of data points. Our reconstruction implementation relies on parallel scientific libr...
Article
Full-text available
This paper provides a mathematical framework for modelling collaborative reputation systems CRSs, which are useful in many fields of electronic commerce. A CRS is an algorithm that, at discrete points in time, receives in input from a set of users some ratings of a set of objects and generates a reputation for both the raters and the evaluated obje...
Article
The scientific and application-oriented interest in the Laplace transform and its inversion is testified by more than 1000 publications in the last century. Most of the inversion algorithms available in the literature assume that the Laplace transform function is available everywhere. Unfortunately, such an assumption is not fulfilled in the applic...