Search results for "transforms"
showing 10 items of 40 documents
On a Continuous Sárközy-Type Problem
2022
Abstract We prove that there exists a constant $\epsilon> 0$ with the following property: if $K \subset {\mathbb {R}}^2$ is a compact set that contains no pair of the form $\{x, x + (z, z^{2})\}$ for $z \neq 0$, then $\dim _{\textrm {H}} K \leq 2 - \epsilon $.
Comparison of two different approaches for harmonic distortion sources assessment
2021
The paper focuses the attention on the comparison of two approaches for power quality assessment in the electric grid. Both approaches are suitable for investigating the harmonic pollution source and discovering if the harmonic source comes from the customer or the utility grid. The two approaches have the same purpose but they are deeply different. The first approach is based on the knowledge of the customer and utility equivalent impedance while the second is based on single point measurement at point of common coupling PCC. In this paper, the advantages and drawbacks of the two approaches are investigated also supported by a case study.
Abnormal textures identification based on digital Hilbert optics methods: fundamental transforms and models
2018
The article presents the abnormal textures identification technology based on structural and statistical models of amplitude-phase images (APIm)– multidimensional data arrays (semantic models) and statistical correlation analysis methods using the generalized discrete Hilbert transforms (DHT)– 2D Hilbert (Foucault) isotropic (HTI), anisotropic (HTA) and total transforms – AP-analysis (APA) to calculate the APIm. The identified fragments of textures are obtained as examples of experimental observation of real mammograms contains areas of pathological tissues. The DHT based information technology as conceptual chart description is discussed and illustrated with DHO domain images. As additiona…
Space-Frequency Quantization for Image Compression With Directionlets
2007
The standard separable 2-D wavelet transform (WT) has recently achieved a great success in image processing because it provides a sparse representation of smooth images. However, it fails to efficiently capture 1-D discontinuities, like edges or contours. These features, being elongated and characterized by geometrical regularity along different directions, intersect and generate many large magnitude wavelet coefficients. Since contours are very important elements in the visual perception of images, to provide a good visual quality of compressed images, it is fundamental to preserve good reconstruction of these directional features. In our previous work, we proposed a construction of critic…
Unique continuation results for certain generalized ray transforms of symmetric tensor fields
2022
Let $I_{m}$ denote the Euclidean ray transform acting on compactly supported symmetric $m$-tensor field distributions $f$, and $I_{m}^{*}$ be its formal $L^2$ adjoint. We study a unique continuation result for the normal operator $N_{m}=I_{m}^{*}I_{m}$. More precisely, we show that if $N_{m}$ vanishes to infinite order at a point $x_0$ and if the Saint-Venant operator $W$ acting on $f$ vanishes on an open set containing $x_0$, then $f$ is a potential tensor field. This generalizes two recent works of Ilmavirta and M\"onkk\"onen who proved such unique continuation results for the ray transform of functions and vector fields/1-forms. One of the main contributions of this work is identifying t…
Analytical solutions of magnetohydrodynamical problems on a flow of conducting fluid in the entrance region of channels in a strong magnetic field šķ…
2014
Darbā iegūti analītiskie atrisinājumi magnetohidrodinamiskiem (MHD) uzdevumiem par elektrovadoša šķidruma plūsmu plakanā un cilindriskā kanālā stiprā magnētiskā laukā gadījumiem, kad šķidrums ietek kanālos caur galīga platuma spraugu vai caur galīga rādiusa atveri kanāla sānu malā. Pamatojoties uz iegūtajiem atrisinājumiem, veikta plūsmas ātruma lauka skaitliskā analīze. Iegūti uzdevumu asimptotiskie atrisinājumi lieliem Hartmana skaitļiem. Turklāt darbā pētīta pilna spiediena spēka šķidruma ieplūdes apgabalā atkarība no funkcijas veida, ar kuru ir uzdots ātruma robežnosacījums. Pētījums veikts analītiski, risinot divas hidrodinamiskas problēmas un divas MHD problēmas par viskoza šķidruma i…
Tablica interaktywna w pracy współczesnego nauczyciela szkoły podstawowej
2018
W obliczu dynamicznych przeobrażeń społecznych oraz wyzwań, przed którymi stoi ludz-kość, a także przeobrażeń w mentalności i podejściu do życia współczesnych dzieci i młodzieży zmianie powinny ulec sposoby oddziaływania szkoły. Wychodząc tym zjawiskom naprzeciw, powinna ona w większym aniżeli dotąd stopniu wykorzystywać nowoczesne technologie eduka-cyjne. Duże możliwości w tym względzie daje np. tablica interaktywna. Odpowiednie jej zastoso-wanie podnosi efektywność pracy nauczyciela, a także zwiększa atrakcyjność zajęć, odpowiadając zapotrzebowaniu uczniów na konkretny rodzaj bodźców i aktywności. Tablica interaktywna staje się powoli codziennością szkoły, jednak istnieje ciągle wiele czy…
Quaternary Reversible Circuit Optimization for Scalable Multiplexer and Demultiplexer
2023
Information loss is generally related to power consumption. Therefore, reducing information loss is an interesting challenge in designing digital systems. Quaternary reversible circuits have received significant attention due to their low-power design applications and attractive advantages over binary reversible logic. Multiplexer and demultiplexer circuits are crucial parts of computing circuits in ALU, and their efficient design can significantly affect the processors’ performance. A new scalable realization of quaternary reversible 4×1 multiplexer and 1×4 demultiplexer, based on quaternary 1-qudit Shift, 2-qudit Controlled Feynman, and 2-qudit Muthukrishnan-Stroud gates, is presented in …
Il primo concorso per il Palazzo di Giustizia a Roma del 1884. Ricostruzione critica del progetto di Ernesto Basile
2019
1. Breve descrizione dell’oggetto di studio Il concorso del Palazzo di Giustizia di Roma si svolge in quattro fasi svolte tra il 1884 e il 1887. Il progetto per il primo concorso, del 1884, redatto dall’allora giovanissimo Ernesto Basile (Palermo 1857-1932), rivela una grande perizia progettuale che trasforma il complesso programma funzionale in un austero edificio in stile neofiorentino. I disegni originari dell’opera, non realizzata, conservati presso la Dotazione Basile del Dipartimento di Architettura dell’Università di Palermo, sono stati oggetto di studio propedeutico alle fasi di analisi, interpretazione e ricostruzione congetturale del modello digitale. 2. Stato dell’arte e riferime…
Una proiezione spaziale per la musica del nostro tempo
2020
Articolo su una proposta progettuale che, svolta come Tesi di Laurea da Sara Sgueglia (relatore Renato Capozzi e Correlatrice Claudia Sansò), prevede per le tre parti del complesso di Nebida - Il Polo, l’ex laveria La Carroccia e l’Approdo - non solo un cambiamento funzionale, ma una mutazione di senso. Ciò trasforma la preesistenza, un esempio di archeologia industriale ubicata nel lato Ovest della Sardegna, in un luogo per acquisire nuove tecniche di registrazione sonora. Progetto vincitore del premio Camerino 2019. Article on a project proposal that, carried out as a thesis by Sara Sgueglia (rapporteur Renato Capozzi and co-rapporteur Claudia Sansò), foresees for the three parts of the N…