Search results for "Geometry"
showing 10 items of 4487 documents
Klein Concert: A Report from a Math-Musical Classroom Experience
2020
Can music help mathematical education? Can some shapes, that challenge visual imagination, be translated into music? I present a pedagogical application of my interdisciplinary research. This concerns a cycle of seminars about mathematics and music I gave in Italy at the Music Conservatory of Palermo and that, in a shortened version, I also gave at Ca’ Foscari University in Venice, at the Conservatory of Livorno, and in the UK, at the University of Greenwich. Seminars included a theoretical section and a workshop. Mathematical concepts helped students formalize their musical knowledge, and music provided an intuitive understanding of mathematical concepts, such as the dualism continuous/dis…
Diorganotin(IV) complexes ofD-galacturonic acid: solid-state and solution-phase structural study
2003
Three diorganotin(IV) complexes of D-galacturonic acid (H2GalA; R = Me, n-Bu, Ph), two of which are new derivatives (R = Me, Ph), have been synthesized and their solid-state and solution-phase investigated by IR, Mossbauer, 1H, 13C and 119Sn NMR spectroscopy. The FTIR data suggest that H2GalA, in the dialkyltin derivatives, behaves as a dianionic ligand, coordinating the tin(IV) atom through an ester-type carboxylate and deprotonated alcoholic hydroxo groups, whereas a bridging carboxylate occurs in the diphenyltin(IV) complex. Octahedral and trigonal bipyramidal local geometries on tin(IV) atoms are proposed for dialkyltin(IV)GalA and diphenyltin(IV)GalA complexes respectively on the basis…
Pants complex, TQFT and hyperbolic geometry
2021
We present a coarse perspective on relations of the $SU(2)$-Witten-Reshetikhin-Turaev TQFT, the Weil-Petersson geometry of the Teichm\"uller space, and volumes of hyperbolic 3-manifolds. Using data from the asymptotic expansions of the curve operators in the skein theoretic version of the $SU(2)$-TQFT, as developed by Blanchet, Habegger, Masbaum and Vogel, we define the quantum intersection number between pants decompositions of a closed surface. We show that the quantum intersection number admits two sided bounds in terms of the geometric intersection number and we use it to obtain a metric on the pants graph of surfaces. Using work of Brock we show that the pants graph equipped with this …
El teorema de Pitàgores en segon d’ESO
2012
El teorema de Pitàgores és un contingut fonamental en l’assignatura de matemàtiques en el currículum d’Educació Secundària. Per tal de conèixer els continguts concrets que pertoquen a este curs, analitzem el que s’establix per Reial Decret al currículum oficial de l’Estat i al de la Comunitat Valenciana. Tindrem també en compte els continguts dels cursos anteriors i posteriors per tal d’evitar repeticions o insuficiències en la matèria. En el primer curs d’ESO s’estudia la fórmula i s’utilitza per a calcular el valor d’un costat d’un triangle rectangle coneguts els altres dos. En segon es demostra esta fórmula i s’utilitza per a determinar l’àrea de polígons; determinar si un triangle és re…
Reasons of irregularity of seed's distribution in the divider heads of air-seeders
2017
ISBN : 978-3-18-092300-0; International audience; Modern seeding equipment must allow to cultivate sizeable areas efficiently and finalize the seeding in a short amount of time. Air-seeder is a solution for a fast seeding: seeds are conveyed from the high-capacity seed hopper to the coulter-bar by an air-stream. Taking into account the complexity of this type of seed drills, they stay little-studied. Few developments have been done on divider headers responsible of distribution accuracy. This paper deals with a study on the influence of divider head geometry and functioning conditions on the seed's distribution accuracy. Moreover, observation of the seed's behaviour is done using a high-spe…
MANIPULATION OF OBJECTS AS INTEGRATION ACTIVITY
2016
The visual disability assumes, in the processes of teaching and learning, a particular connotation for the specificity that over the years the vision in the overall structure of knowledge has had. The whole western tradition on the knowledge stood on a "oculocentric" vision of knowledge. The view has always been considered the “sense for excellence". An educational activity, therefore, that emphasizes and promotes strategies of inclusion / integration of students with visual impairment is significant and essential to the whole class group. We present here an experimentation with primary school children: in a closed bag, there are objects of everyday life: every time a child extracts an obje…
Directionlets: Anisotropic Multidirectional representation with separable filtering
2006
In spite of the success of the standard wavelet transform (WT) in image processing in recent years, the efficiency of its representation is limited by the spatial isotropy of its basis functions built in the horizontal and vertical directions. One-dimensional (1-D) discontinuities in images (edges and contours) that are very important elements in visual perception, intersect too many wavelet basis functions and lead to a nonsparse representation. To efficiently capture these anisotropic geometrical structures characterized by many more than the horizontal and vertical directions, a more complex multidirectional (M-DIR) and anisotropic transform is required. We present a new lattice-based pe…
Dificultades de interpretación y de uso de los arrastres en Cabri 3d por estudiantes de E.S.O.
2012
La presente memoria corresponde al Trabajo Fin de Máster demandado dentro del programa del Máster de Investigación de Didácticas Específicas de la Universidad de Valencia. En este proyecto pretendemos contribuir a la mejora de la calidad docente a través de una mejor comprensión del aprendizaje en entornos colaborativos con programas de geometría dinámica. La aparición de programas de geometría dinámica en 3D (PGD 3D) ofrece la oportunidad de utilizarlos en el ámbito escolar. En este sentido, resulta pertinente hacerse las siguientes preguntas genéricas a partir de las cuales surgirán nuestras preguntas de investigación: § ¿Cuáles son la naturaleza y el alcance de la integración de PGD 3D e…
LA GEOMETRIE FRACTALE - UN NOUVEL OUTIL POUR EVALUER LE ROLE DE LA MORPHOLOGIE DES RESEAUX DE TRANSPORT PUBLIC DANS L'ORGANISATION SPATIALE DES AGGLO…
1998
National audience
Embeddings of graph braid and surface groups in right-angled Artin groups and braid groups
2003
We prove by explicit construction that graph braid groups and most surface groups can be embedded in a natural way in right-angled Artin groups, and we point out some consequences of these embedding results. We also show that every right-angled Artin group can be embedded in a pure surface braid group. On the other hand, by generalising to right-angled Artin groups a result of Lyndon for free groups, we show that the Euler characteristic -1 surface group (given by the relation x^2y^2=z^2) never embeds in a right-angled Artin group.