Search results for " GEOMETRIA"

Temari Balls, Spheres, SphereHarmonic: From Japanese Folkcraft to Music

2022

Temari balls are traditional Japanese toys and artworks. The variety of their geometries and tessellations can be investigated formally and computationally with the means of combinatorics. As a further step, we also propose a musical application of the core idea of Temari balls. In fact, inspired by the classical idea of music of spheres and by the CubeHarmonic, a musical application of the Rubik’s cube, we present the concept of a new musical instrument, the SphereHarmonic. The mathematical (and musical) description of Temari balls lies in the wide background of interactions between art and combinatorics. Concerning the methods, we present the tools of permutations and tessellations we ado…

Automatic social distance estimation for photographic studies: Performance evaluation, test benchmark, and algorithm

2022

The social distancing regulations introduced to slow down the spread of COVID-19 virus directly affect a basic form of non-verbal communication, and there may be longer term impacts on human behavior and culture that remain to be analyzed in proxemics studies. To obtain quantitative results for such studies, large media and/or personal photo collections must be analyzed. Several social distance monitoring methods have been proposed for safety purposes, but they are not directly applicable to general photo collections with large variations in the imaging setup. In such studies, the interest shifts from safety to analyzing subtle differences in social distances. Currently, there is no suitabl…

Hyperbolinen geometria ja Fuchsin ryhmät

2015

Circular Forms in Aleksis Kivi’s Texts

2016

In this paper, I identify and analyse regular geometric forms that appear in nineteenth-century Finnish author Aleksis Kivi’s texts. His characters and his narrators exemplify these forms to the reader. The characters’ environments are geometrically described, mapped and constructed in Seven Brothers, and geometric figures also exist in several of Kivi’s novels, plays and poems. Circles are the most common of these figures. Thus, I concentrate on expanding and converging regular geometric forms that connect to circles. peerReviewed

A remark on two notions of flatness for sets in the Euclidean space

2021

In this note we compare two ways of measuring the $n$-dimensional "flatness" of a set $S\subset \mathbb{R}^d$, where $n\in \mathbb{N}$ and $d>n$. The first one is to consider the classical Reifenberg-flat numbers $\alpha(x,r)$ ($x \in S$, $r>0$), which measure the minimal scaling-invariant Hausdorff distances in $B_r(x)$ between $S$ and $n$-dimensional affine subspaces of $\mathbb{R}^d$. The second is an `intrinsic' approach in which we view the same set $S$ as a metric space (endowed with the induced Euclidean distance). Then we consider numbers ${\sf a}(x,r)$'s, that are the scaling-invariant Gromov-Hausdorff distances between balls centered at $x$ of radius $r$ in $S$ and the $n$-dimensi…

Visuaalinen tangentti lukion pitkässä matematiikassa

2017

Opinnäytetyössä selvitellään lukion pitkän matematiikan opiskelijoiden käsityksiä visuaalisesta tangenttisuorasta (lyh. tangentista). Työ sisältää tietokoosteen tutkielman aihepiirin visuaalisesta tangentista. Lukio-opiskelijoiden käsityksiä tangentista esitellään Tallin 1980-luvun tietokoneavusteisesta opetuskokeilusta ja Bizan 2000-luvun tutkimuksesta. Empiirisessä tutkimuksessa tutkittiin lukion pitkän matematiikan oppikirjasarjan visuaalista tangenttia. Ihmiset ymmärtävät aistein havainnoitavat kohteet pääosin intuition avulla, kun taasen matemaattiset käsitteet voidaan ymmärtää aksioomien, määritelmien ja lauseiden pohjalta. Kuitenkin Bizan laaja tutkimus osoittaa, että lukio-opiskelij…

"Mirrors"

2021

[no abstract]

Saccheri vu par Corrado Segre en Italie et par Mansion et Bosmans en Belgique

2010

Brigaglia Aldo, Gaino Bruna, Radelet-de-Grave Patricia. Saccheri vu par Corrado Segre en Italie et par Mansion et Bosmans en Belgique. In: Bulletin de la Classe des sciences, tome 21, 2010. Le Père Henri Bosmans SJ (1852-1928) historien des mathématiques. pp. 83-104.

Quasi-Homogeneous Linear Systems on with Base Points of Multiplicity multiplicity 5

2003

In this paper we consider linear systems of ℙ2 with all but one of the base points of multiplicity 5. We give an explicit way to evaluate the dimensions of such systems

Impaired geometric properties of tibia in older women with hip fracture history.

2007

This study evaluated side-to-side differences in tibial mineral mass and geometry in women with previous hip fracture sustained on average 3.5 years earlier. Both tibial mineral mass and geometry were found to be reduced in the fractured leg. INTRODUCTION: The purpose of this study was to evaluate side-to-side differences in tibial mineral mass and geometry after hip fracture and to assess the determinants of such differences. METHODS: Thirty-eight 60- to 85-year-old women with a previous hip fracture and 22 same-aged control women without fractures participated in the study. Bone characteristics of the distal tibia and tibial shaft of both legs were assessed using pQCT in order to compare …