• Títol: Stark-Heegner points and p-adic L-functions.
• Doctorand: Daniele Casazza.
• Directors: Victor Rotger i Jean Gillibert.
• Dia : 28-10-2016.
• Hora : 17 h.
• Lloc : Sala d’Actes de l’FME, Edifici U, Campus Sud.

Programa de doctorat en Matemàtica Aplicada. 

Per a més informació:  http://doctorat.upc.edu/tesi/llistats-de-tesis/tesis-autoritzades-per-lectura.

Abstract

General methods from diophantine geometry have been very successful in proving finiteness results for points of algebraic curves with values in number fields. Those results however are in general not effective, for deep reasons, and this prevents from proving triviality (and not only finiteness) of relevant sets of rational points. In this talk I will explain how the situation can be much better in the case of modular curves, by using specific arakelovian methods.

Abstract

Distributed storage allows to outsource a document to the cloud such that multiple users can easily access the file. The protection of the document stored relies on secret sharing, which generates and distributes shares of the document to the storage servers. However, the users have to trust that a certain amount of storage servers behaves honestly and do not lose (retrievability) or reveal (confidentiality) the document. To address this so called social secret sharing schemes were developed that allow to adjust the distribution of shares according to the experience made with the involved storage servers. In this work, we provide a framework called AS$^3$ that allows to build social secret sharing schemes based on dynamic secret sharing. The resulting protocol has more freedom in adjusting the parameters of the shares distribution and therefore leads to more efficient and accurate solutions as well as an optimal storage consumption. Furthermore, we provide measures to detect and to prevent that the document is lost or accidentally revealed to individual storage servers. We also demonstrate how to compute trust values for storage servers, how to initialize trust values for newcomers, and provide a proof of concept implementation

Més informació: http://www.ub.edu/sga/seminari1617/kondo.pdf.

Més informació: http://www.ub.edu/sga/seminari1617/garciafritz.pdf.

Se celebrarà dijous 20 d'octubre de 2016, de 18 a 20 h a l'auditori de Neàpolis de Vilanova i la Geltrú, a càrrec de Joan Gómez i Urgellés, matemàtic, doctor en pedagogia i professor a l'UPC.

En la conferència farem un viatge pels diferents sistemes i codis de xifrar i desxifrar missatges secrets, des dels temps dels egipcis i dels romans fins a la màquina Enigma de la Segona Guerra Mundial i acabant amb els sofisticats sistemes actuals basats en l’anomenat sistema RSA.

La conferència està adreçada a tots als públics, majors i menors d’edat, pares, mares, nens i nenes... amb la voluntat de passar un a estona amena i entretinguda desxifrant codis de seguretat tot fent d’aprenents d’espies.

Inscripció gratuïta. Places limitades. Link 

El dimecres 19 a la 13 h a la Sala Multimèdia de l'ETSETB, Campus Nord, tindrà lloc una sessió informativa sobre les beques Fulbright per a realitzar estudis de màster als EEUU.

La nova convocatòria s'obrirà al gener del 2017.

Enllaç a la convocatòria: http://fulbright.es/convocatorias/ver/1484/ampliacion-de-estudios/2017-2018.

Title: Are higher order Delaunay triangulations useful in practice? 

Speaker: Rodrigo I. Silveira, Universitat Politècnica de Catalunya.

Abstract

Abstract: The Delaunay triangulation is the standard choice for building polyhedral terrains, also known as triangulated irregular networks (TINs), to represent terrain surfaces. However, the Delaunay triangulation is based only on the 2D coordinates of the data points, ignoring their elevation. It has long been recognized that sometimes it may be beneficial to use other, non-Delaunay, criteria to build TINs. Data-dependent triangulations were introduced decades ago to address this. However, they are rarely used in practice, mostly because the optimization of data-dependent criteria often results in triangulations with many thin and elongated triangles. Recently, in the field of computational geometry, higher order Delaunay triangulations (HODTs) were introduced, trying to tackle both issues at the same time-data-dependent criteria and good triangle shape. Nevertheless, most previous studies about them have been limited to theoretical aspects. In this work we present the first extensive experimental study on the practical use of HODTs, as a tool to build data-dependent TINs. We present experiments with two USGS terrains that show that HODTs can give significant improvements over the Delaunay triangulation for the criteria identified as most important for data-dependent triangulations. The resulting triangulations have data-dependent values comparable to those obtained with pure data-dependent approaches, without compromising the shape of the triangles, and are faster to compute. 

Activities are regularly announced at: http://www-ma2.upc.edu/dccg/upc-seminar-on-computational-geometry.

• Títol: Schottky problem and abelian varieties of CM-type.
• Estudiant: Anna Somoza.
• Director: Joan Carles Lario.
• Dia : 11/10/2016.
• Hora : 11:00.
• Lloc : Sala de Juntes de l'FME, Edifici U, Campus Sud de la UPC.

Amb l'objectiu de millorar els resultats que la UPC obté en la secció d'impacte de les propostes, en col·laboració amb el CDTI la UPC us convida a participar en el Workshop "Com millorar la secció d'impacte a les propostes H2020". Podeu enviar les vostres preguntes perquè siguin tractades durant la sessió a través del formulari d'inscripció.

• Data 5 d'octubre, 10:00 h a 12:30 h.
• Lloc: Aula Màster, Campus Nord de la UPC.
• Data límit d'inscripció: 27 de setembre.

Enllaç per a la inscripció: https://genwebv4.upc.edu/ctt/ca/ope-projectes-europeus/formularis/workshop-5-octubre-2016.