Davide Bianchi, Alessandro Buccini, Marco Donatelli, Stefano Serra‐Capizzano,
Fractional Tikhonov regularization methods have been recently proposed to reduce the oversmoothing property of the Tikhonov regularization in standard form, in order to preserve the details of the approximated solution. Their regularization and convergence properties have been previously investigated showing that they are of optimal order. This paper provides saturation and converse results on their convergence rates. Using the same iterative refinement strategy of iterated Tikhonov regularization, ...
Tópico(s): Thermoelastic and Magnetoelastic Phenomena
2015 - IOP Publishing | Inverse Problems
Alessandro Buccini, Marco Donatelli, Lothar Reichel,
Tikhonov regularization is one of the most popular approaches to solving linear discrete ill-posed problems. The choice of the regularization matrix may significantly affect the quality of the computed solution. When the regularization matrix is the identity, iterated Tikhonov regularization can yield computed approximate solutions of higher quality than (standard) Tikhonov regularization. This paper provides an analysis of iterated Tikhonov regularization with a regularization matrix different from ...
Tópico(s): Statistical and numerical algorithms
2017 - Wiley | Numerical Linear Algebra with Applications
Alessandro Buccini, Marco Donatelli, Ronny Ramlau,
In many inverse problems the operator to be inverted is not known precisely, but only a noisy version of it is available; we refer to this kind of inverse problem as semiblind. In this article, we propose a functional which involves as variables both the solution of the problem and the operator itself. We first prove that the functional, even if it is nonconvex, admits a global minimum and that its minimization naturally leads to a regularization method. Later, using the popular alternating direction ...
Tópico(s): Advanced Image Processing Techniques
2018 - Society for Industrial and Applied Mathematics | SIAM Journal on Scientific Computing
Alessandro Buccini, Marco Donatelli,
Iterative soft thresholding algorithms combine one step of a Landweber method (or accelerated variants) with one step of thresholding of the wavelet (framelet) coefficients. In this paper, we improve these methods by using the framelet multilevel decomposition for defining a multigrid deconvolution with grid transfer operators given by the low-pass filter of the frame. Assuming that an estimate of the noise level is available, we combine a recently proposed iterative method for ℓ2-regularization with ...
Tópico(s): Sparse and Compressive Sensing Techniques
2020 - | ETNA - Electronic Transactions on Numerical Analysis
Davide Bianchi, Alessandro Buccini, Marco Donatelli, Emma Randazzo,
Image deblurring is a relevant problem in many fields of science and engineering. To solve this problem, many different approaches have been proposed, and, among the various methods, variational ones are extremely popular. These approaches substitute the original problem with a minimization problem where the functional is composed of two terms, a data fidelity term and a regularization term. In this paper we propose, in the classical non-negative constrained $\ell^2$-$\ell^1$ minimization framework, ...
Tópico(s): Numerical methods in inverse problems
2021 - | ETNA - Electronic Transactions on Numerical Analysis
Marco R. Buccini, Matthew Piggott,
ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXTA Four-Step Total Synthesis of RadermacholMarco Buccini and Matthew J. Piggott*View Author Information School of Chemistry & Biochemistry, The University of Western Australia, Perth, Australia*E-mail: [email protected]Cite this: Org. Lett. 2014, 16, 9, 2490–2493Publication Date (Web):April 21, 2014Publication History Received23 March 2014Published online21 April 2014Published inissue 2 May 2014https://pubs.acs.org/doi/10.1021/ol500862whttps://doi.org/10.1021/ ...
Tópico(s): Bioactive Compounds and Antitumor Agents
2014 - American Chemical Society | Organic Letters
Marco R. Buccini, Kathryn A. Punch, Belinda J. Kaskow, Gavin R. Flematti, Brian W. Skelton, Lawrence J. Abraham, Matthew Piggott,
Antrocamphin A and B, and (±)- epi -antrodioxolanone have been synthesised from a common precursor. Antrocamphin A displays anti-inflammatory activity but is also cytotoxic.
Tópico(s): Biological and pharmacological studies of plants
2013 - Royal Society of Chemistry | Organic & Biomolecular Chemistry
Marco R. Buccini, Shi Yuan Jeow, Lindsay T. Byrne, Brian W. Skelton, Tuan Minh Nguyen, Christina L. L. Chai, Matthew Piggott,
Abstract Three bisannulation strategies have been used to rapidly construct pentacyclic benzo‐fused pyrrolo[4,3,2‐ mn ]acridines, similar to several biologically active natural products. The key steps involve Michael substitution of 2,3‐dichloro‐1,4‐naphthoquinone with o ‐nitrophenylacetic acid derivatives, followed by domino amino‐Michael substitutions/cyclisations. The most efficient of these syntheses provided a model compound ( 1 ) including the ABCD ring‐system of alpkinidine, in just three steps ...
Tópico(s): Synthesis and Biological Activity
2013 - Wiley | European Journal of Organic Chemistry
Yaru Fan, Alessandro Buccini, Marco Donatelli, Ting‐Zhu Huang,
Compressive sensing (CS) aims at reconstructing high dimensional data from a small number of samples or measurements. In this paper, we propose the minimization of a non-convex functional for the solution of the CS problem. The considered functional incorporates information on the self-similarity of the image by measuring the rank of some appropriately constructed matrices of fairly small dimensions. However, since the rank minimization is a NP hard problem, we consider, as a surrogate function for ...
Tópico(s): Photoacoustic and Ultrasonic Imaging
2018 - Springer Science+Business Media | Advances in Computational Mathematics
Davide Bianchi, Alessandro Buccini, Marco Donatelli, Stefano Serra‐Capizzano,
Abstract We consider linear operator equations of the form where $K:{\cal X}\to{\cal Y}$ is a compact linear operator between Hilbert spaces ${\cal X} \hbox{ and } {\cal Y}.$ We assume y to be attainable, i.e., that problem (1) has a solution x † = K † y of minimal norm. Here K † denotes the (Moore‐Penrose) generalized inverse operator of K , which is unbounded when K is compact, with infinite dimensional range. Hence problem (1) is ill‐posed and has to be regularized in order to compute a numerical solution. We want ...
Tópico(s): Numerical methods in inverse problems
2015 - Wiley | PAMM
Alessandro Buccini, Pietro Dell’Acqua, Marco Donatelli,
The Alternating Direction Multipliers Method (ADMM) is a very popular algorithm for computing the solution of convex constrained minimization problems. Such problems are important from the application point of view, since they occur in many fields of science and engineering. ADMM is a powerful numerical tool, but unfortunately its main drawback is that it can exhibit slow convergence. Several approaches for its acceleration have been proposed in the literature and in this paper we present a new general ...
Tópico(s): Image and Signal Denoising Methods
2019 - Springer Science+Business Media | Numerical Algorithms
Alessandro Buccini, Omar De la Cruz Cabrera, Marco Donatelli, Andrea Martinelli, Lothar Reichel,
We describe a computational method for parameter estimation in linear regression, that is capable of simultaneously producing sparse estimates and dealing with outliers and heavy-tailed error distributions. The method used is based on the image restoration method proposed in Huang et al. (2017) [13]. It can be applied to problems of arbitrary size. The choice of certain parameters is discussed. Results obtained for simulated and real data are presented.
Tópico(s): Image and Signal Denoising Methods
2020 - Elsevier BV | Applied Numerical Mathematics
Alessandro Buccini, Marco Donatelli, F. Ferri,
Tópico(s): Image and Signal Denoising Methods
2017 - Springer Science+Business Media | Journal of Scientific Computing
Davide Bianchi, Alessandro Buccini, Marco Donatelli,
Regularizing preconditioners for accelerating the convergence of iterative regularization methods and improving their accuracy have been extensively investigated both in Hilbert and Banach spaces. For deconvolution problems, the classical approach defines preconditioners based on the circular convolution. On the other hand, for $$\ell _2$$ regularization methods, it has been recently shown that a preconditioner preserving the structure of the convolution operator can be more effective. Such a preconditioner ...
Tópico(s): Numerical methods in inverse problems
2019 - Springer International Publishing | Springer INdAM series
Giuseppe Argenziano, Caterina Catricalà, Marco Ardigò, Pierluigi Buccini, Paola De Simone, Laura Eibenschutz, Angela Ferrari, Giustino Mariani, Vitaliano Silipo, Isabella Sperduti, Iris Zalaudek,
Most dermoscopic algorithms to diagnose melanoma were established more than 10 years ago and have been tested primarily on clear-cut melanomas and excised melanocytic naevi.To assess the diagnostic performance of pattern analysis and seven-point checklist on lesions that reflect the current clinical setting, compared with a revised seven-point checklist with a lower threshold for excision.Eight experienced dermatologists viewed dermoscopic images of 100 excised melanomas, 100 excised naevi and 100 ...
Tópico(s): Cutaneous lymphoproliferative disorders research
2010 - Oxford University Press | British Journal of Dermatology
Giuseppe Argenziano, Caterina Catricalà, Marco Ardigò, Pierluigi Buccini, Paola De Simone, Laura Eibenschutz, Angela Ferrari, Giustino Mariani, Vitaliano Silipo, Iris Zalaudek,
To assess the outcome on management recommendations of a comparative approach vs a morphologic approach in evaluating dermoscopic images of lesions from a series of patients with multiple nevi.In a 2-step study, 6 experienced dermoscopists were asked to provide management recommendations (excision or follow-up) for a series of lesions from patients with multiple nevi based on dermoscopic images of the lesions. In the first step, participating dermoscopists evaluated individual images of lesions based ...
Tópico(s): Nail Diseases and Treatments
2011 - American Medical Association | Archives of Dermatology
Marina Agozzino, Angela Ferrari, Carlo Cota, Chiara Franceschini, Pierluigi Buccini, L. Eibenshutz, Marco Ardigò,
The differential diagnosis between regressing nevi and melanoma might be challenging; regressing areas can represent a confounding factor for the diagnosis and the histology still remain mandatory to rule out melanoma. Reflectance confocal microscopy may add valuable information by revealing features suggestive of the nature of the melanocytic proliferation.To assess the impact of confocal microscopy in the management of regressive melanocytic lesions.The dermoscopic analysis of 92 melanocytic lesions ...
Tópico(s): Cutaneous lymphoproliferative disorders research
2017 - Wiley | Skin Research and Technology
Alessandro Buccini, Marco Donatelli, Lothar Reichel, Weihong Zhang,
Abstract Discrete ill‐posed inverse problems arise in many areas of science and engineering. Their solutions are very sensitive to perturbations in the data. Regularization methods aim at reducing this sensitivity. This article considers an iterative regularization method, based on iterated Tikhonov regularization, that was proposed in M. Donatelli and M. Hanke, Fast nonstationary preconditioned iterative methods for ill‐posed problems, with application to image deblurring, Inverse Problems , 29 (2013), ...
Tópico(s): Photoacoustic and Ultrasonic Imaging
2020 - Wiley | Numerical Linear Algebra with Applications
Produção Nacional
Revisado por pares
Gabriela Buccini, Stefanie Eugênia dos Anjos Coelho Kubo, Jéssica Pedroso, Juracy Bertoldo, Alberto Sironi, Marcos Barreto, Rafael Pérez‐Escamilla, Sônia Isoyama Venâncio, Muriel Bauermann Gubert,
Abstract Providing an enabling nurturing care environment for early childhood development (ECD) that cuts across the five domains of the Nurturing Care Framework (i.e., good health, adequate nutrition, opportunities for early learning, security and safety and responsive caregiving) has become a global priority. Brazil is home to approximately 18.5 million children under 5 years of age, of which 13% are at risk of poor development due to socio‐economic inequalities. We explored whether the Early Childhood ...
Tópico(s): Poverty, Education, and Child Welfare
2021 - Wiley | Maternal and Child Nutrition
Stefano Aleotti, Alessandro Buccini, Marco Donatelli,
Image reconstruction problems, like image deblurring and computer tomography, are usually ill-posed and require regularization. A popular approach to regularization is to substitute the original problem with an optimization problem that minimizes the sum of two terms, an ℓ2 term and an ℓq term with 0<q≤1. The first penalizes the distance between the measured data and the reconstructed one, the latter imposes sparsity on some features of the computed solution. In this work, we propose to use the ...
Tópico(s): Mathematical Analysis and Transform Methods
2023 - Elsevier BV | Applied Numerical Mathematics
Anna Carbone, Flavia Persechino, Giovanni Paolino, Carlo Cota, Paolo Piemonte, Chiara Franceschini, Laura Eibenschutz, Angela Ferrari, Pierluigi Buccini, Pasquale Frascione, Stefano Calvieri, Marco Ardigò,
BACKGROUND: Enlarging melanocytic lesions with peripheral globular pattern (EMLPGP) are a pitfall in dermoscopy. Our aim was to evaluate the meaning of EMLPGP and to assess the use of dermoscopy and reflectance confocal microscopy (RCM) in order to improve the clinical management of this subtype of melanocytic lesions.METHODS: A total of 135 EMLPGP were recruited and, accordingly to the dermoscopy features, were removed; later, an expert dermoscopist reviewed the lesions blinded to histology. Moreover, ...
Tópico(s): Cutaneous lymphoproliferative disorders research
2021 - | Italian Journal of Dermatology and Venereology
Produção Nacional
Revisado por pares
Marco Ardigò, Rosana Bortoli Buffon, Alon Scope, Carlo Cota, Pierluigi Buccini, Enzo Berardesca, Giovanni Pellacani, Ashfaq A. Marghoob, Melissa Gill,
Clear cell acanthoma (CCA) is a rare, benign neoplasm of unknown etiology, whose dermoscopic and histological features have been previously described. Usually, CCA can be diagnosed by clinical and dermoscopic examination. In some cases, diagnosis remains uncertain, and histological examination is needed. The aim of this paper was to describe the features of reflectance confocal microscopy (RCM) in diagnosing CCA, compare them with findings on dermoscopy and histology, and evaluate their possible usefulness ...
Tópico(s): Nonmelanoma Skin Cancer Studies
2009 - Lippincott Williams & Wilkins | Dermatologic Surgery
Marco R. Buccini, Louisa Tham, Francis Dhoro, Brian W. Skelton, Craig M. Williams, Matthew Piggott,
Model chemistry involving the bisannulation of 2,3-dichloro-1,4-naphthoquinone with the ester enolate derived from ethyl o-nitrophenylacetic acid, which rapid assembled the ABCD ring system of a pentacyclic pyrroloacridine, has been applied to the attempted synthesis of the marine natural product alpkinidine. The reaction of ethyl o-nitrophenylacetic acid with 6,7-dichloro-2-methylisoquinoline-1,5,8(2H)-trione, required to extend the model strategy to alpkinidine, was unfruitful, giving only complex ...
Tópico(s): Synthesis of Indole Derivatives
2022 - American Chemical Society | ACS Omega
Lucia Pedace, Paola De Simone, Marco Castori, Isabella Sperduti, Vitaliano Silipo, Laura Eibenschutz, Carmelilia De Bernardo, Pierluigi Buccini, Elvira Moscarella, Chiara Panetta, Angela Ferrari, Paola Grammatico, Caterina Catricalà,
CDKN2A is the most common, most penetrant gene whom germline mutations predisposing to cutaneous familial melanoma (FAM). Multiple primary melanoma (MPM), early age at onset, >2 affected members and pancreatic cancer are consistent features predicting positive test. However, the impact that cumulative clinical features have on the likelihood of molecular testing is unknown. In this work, genotype–phenotype correlations focused on selected clinical features were performed in 100 Italian FAM unrelated ...
Tópico(s): Immunotherapy and Immune Responses
2011 - Elsevier BV | Cancer Epidemiology
Alessandro Buccini, Marco Donatelli, Lucas Onisk, Lothar Reichel,
Tópico(s): Iterative Methods for Nonlinear Equations
2025 - Springer Science+Business Media | Numerical Algorithms
Alessandro Buccini, Marco Donatelli, Marco Ratto,
Tópico(s): Advanced X-ray and CT Imaging
2025 - Multidisciplinary Digital Publishing Institute | Symmetry
Stefania Buccini, Marco Cerruti,
Tópico(s): Historical and Literary Analyses
2002 - American Association of Teachers of Italian | Italica
Produção Nacional
Revisado por pares
Gabriela Buccini, Marcos Barreto, Alberto Sironi, Juracy Bertoldo, Joao Godim, Jéssica Silva, Stefanie Eugênia dos Anjos Campos COELHO, Muriel Bauermann Gubert,
Early inequities in Early Childhood Development (ECD) are linked to inequalities across the five regions and within the 5570 municipalities in Brazil. We aimed to operationalize an index (IMAPI) to assess and monitor the enabling environment for nurturing care at the regional and municipal level in Brazil using existing national databases. We followed three steps to operationalize IMAPI. I) Selection of indicators. The literature review guided the identification of existing indicators to translate ...
Tópico(s): Breastfeeding Practices and Influences
2020 - Elsevier BV | Current Developments in Nutrition
Daniele Passeri, Pierfrancesco Atanasio, Anacleto Proietti, Chiara Mancini, Flavio Cognigni, Giancarlo La Penna, Luca Buccini, Marco Rossi, Anna Chiara Turco, Marilena D’Amato, Angela Sorbo, Simone Dinarelli, Giulia D’Ettorre, Federica Aureli,
Tópico(s): Gold and Silver Nanoparticles Synthesis and Applications
2024 - Elsevier BV | Applied Food Research
Alessandro Buccini, Marco Donatelli, Lothar Reichel,
This work considers some theoretical and computational aspects of the recent paper (Buccini et al., 2021), whose aim was to relax the convergence conditions in a previous work by Donatelli and Hanke, and thereby make the iterative method discussed in the latter work applicable to a larger class of problems. This aim was achieved in the sense that the iterative method presented convergences for a larger class of problems. However, while the analysis presented is correct, it does not establish the ...
Tópico(s): Matrix Theory and Algorithms
2022 - Elsevier BV | Journal of Computational and Applied Mathematics