Matematiikan ja systeemianalyysin laitos

Ajankohtaista

Esitelmiä, seminaareja ja väitöksiä

* Seuraavan viikon tapahtumat merkitty tähdellä

Cintia Pacchiano
Regularity properties for quasi-minimizers of a (p,q)-Dirichlet integral
Monday 07 December 2020,   10:15,   M237
Seminar on analysis and geometry

Lauri Hitruhin
Boundary behaviour of conformal and quasiconformal mappings
Monday 07 December 2020,   14:15,   M237
Seminar on analysis and geometry

Dissertation
Henri Södergård (Aalto University)
Image deblurring by numerical linear algebra (BSc thesis)
Wednesday 09 December 2020,   14:15,   https://aalto.zoom.us/j/67899163157
When taking a photograph, we usually want the resulting image to be a faithful reconstruction of the reality we see with our own eyes. However, almost all images will inevitably suffer from some form of imperfections such as blurriness. To fix this, we can deblur the image employing methods and techniques from numerical linear algebra to mathematically. This way, we can restore the maximum amount of information about the true image from a blurry image. In this talk, I plan to introduce some basic concepts in image deblurring, including the naive solution, the point spread function, spectral filtering (such as Truncated Singular Value Decomposition or the Tikhonov method) and regularisation methods (such as Generalised Cross Validation, the Discrepancy Principle and the L-Curve Criterion). I will also present the results of some experiments that I have run to compare some of these methods in practice, by testing them on some blurred images.
BSc Seminar

Napoleon Freitas Paajanen
TBA
Monday 14 December 2020,   10:15,   M237
Seminar on analysis and geometry

Kristian Moring
TBA
Monday 14 December 2020,   14:15,   M237
Seminar on analysis and geometry

Past events

Dr Jeta Molla (Aalto University)
Numerical methods for the stochastic wave equation
Tuesday 24 November 2020,   16:00,   https://aalto.zoom.us/j/68911259210
Further information
The objective of this talk is to propose a full discretization for the stochastic wave equation. More specifically, the discontinuous Galerkin finite element method is used in space and analyzed in a semigroup framework, and an explicit stochastic position Verlet scheme is used for the temporal approximation. Numerical experiments illustrate our theoretical results on strong convergence rates. Further, we analyze and bound the expected energy and numerically show excellent agreement with the energy of the exact solution. Join Zoom Meeting https://aalto.zoom.us/j/68911259210 Meeting ID: 689 1125 9210
Aalto Stochastics & Statistics Seminar / Leskelä

Emma-Karoliina Kurki
Integral estimates on Whitney chains
Monday 09 November 2020,   14:15,   M237
Seminar on analysis and geometry

Kim Myyryläinen
Median-type John–Nirenberg spaces
Monday 09 November 2020,   10:15,   M237
Seminar on analysis and geometry

Dissertation
Mohamed Taoufiq Damir
Well-rounded lattices and applications to physical layer security (Doctoral defence)
Friday 06 November 2020,   15:00,   Zoom https://aalto.zoom.us/j/65632983027
Further information
ANTA

Julian Weigt
The dyadic maximal function has bounded variation
Monday 02 November 2020,   14:15,   M237
Seminar on analysis and geometry

Carlos Mudarra
Extensions of jets with smooth convex functions and applications
Monday 02 November 2020,   10:15,   M237
Seminar on analysis and geometry

Prashanta Garain
Nonexistence of variational minimizers related to a quasilinear singular problem in metric measure spaces
Monday 05 October 2020,   14:15,   M237
Seminar on analysis and geometry

Sauli Lindberg
Convex integration in magnetohydrodynamics
Monday 05 October 2020,   10:15,   M237
Seminar on analysis and geometry

Afrin Hossain
Fatou and Julia sets in Rational Iteration (kandiesitelmä)
Monday 21 September 2020,   13:15,   M237

Oona Oinonen
Dihedraalisen piilotetun aliryhmän ongelma (kandiesitelmä)
Monday 21 September 2020,   11:00,   Zoom https://aalto.zoom.us/j/63992296777
ANTA

Antti Immonen
Secure Distributed Matrix Multiplication (BSc presentation)
Monday 21 September 2020,   10:15,   Zoom https://aalto.zoom.us/j/63992296777
ANTA

Kalle Kytölä
Euler integrals and a quantum group
Monday 31 August 2020,   15:45,   https://aalto.zoom.us/j/62494927603
mathematical physics end-of-summer seminar day (Kytölä)

Shinji Koshida
Point processes and fermionic algebras
Monday 31 August 2020,   15:00,   https://aalto.zoom.us/j/62494927603
mathematical physics end-of-summer seminar day (Kytölä)

Eveliina Peltola
On large deviations of multiple SLEs
Monday 31 August 2020,   14:15,   https://aalto.zoom.us/j/62494927603
mathematical physics end-of-summer seminar day (Kytölä)

Aapo Pajala
Euclidean Distance Geometry and Its Applications in 3D Genome Reconstruction (Bachelor thesis presentation)
Monday 31 August 2020,   14:00,   https://aalto.zoom.us/j/69001841503

Konstantin Izyurov
Asymptotics of determinants of discrete Laplacians
Monday 31 August 2020,   13:30,   https://aalto.zoom.us/j/62494927603
mathematical physics end-of-summer seminar day (Kytölä)

Tuomas Tuukkanen
Probabilistic Liouville conformal field theory
Monday 31 August 2020,   11:45,   https://aalto.zoom.us/j/62494927603
mathematical physics end-of-summer seminar day (Kytölä)

Osama Abuzaid
TBA
Monday 31 August 2020,   11:00,   https://aalto.zoom.us/j/62494927603
mathematical physics end-of-summer seminar day (Kytölä)

Nerissa Shakespeare
Äärellisistä heijastusryhmistä (kandiesitelmä)
Monday 31 August 2020,   10:00,   https://aalto.zoom.us/j/64382365198
matematiikan kandiseminaari

Perttu Saarela
Hansen polytopes of split graphs (Bachelor thesis presentation)
Friday 28 August 2020,   11:30,   U5 (U147)
https://aalto.zoom.us/j/61788754640

Kai Hippi
Tutte-polynomien laskeminen (Kandiesitelmä)
Friday 28 August 2020,   10:45,   U5 (U147)
https://aalto.zoom.us/j/61788754640

Meri Aho
Cyclic flats and graphical matroids (Bachelor thesis presentation)
Friday 28 August 2020,   10:00,   U5 (U147)
https://aalto.zoom.us/j/61788754640

Selim Virtanen
Johdatus p-adisiin lukuihin ja lokaali-globaali-periaatteeseen (kandiesitelmä)
Thursday 27 August 2020,   14:00,   U5 and Zoom https://aalto.zoom.us/j/64748623259
ANTA

Okko Makkonen
Tuplaavuus ja Sobolevin upotus (Kandityöesitelmä)
Thursday 27 August 2020,   13:15,   U5
Kandiseminaari

Joonas Laaksonen
Legendren sarjakehitelmän suppenemisesta 2D:ssä (Kandiesitelmä)
Thursday 27 August 2020,   11:00,   https://aalto.zoom.us/j/67335018504
Kandiesitelmä

Etna Lindy
Parameter estimation for group-based phylogenetic models in the probability and Fourier coordinates (Bachelor thesis presentation)
Wednesday 26 August 2020,   11:00,   zoom
https://aalto.zoom.us/j/69001841503

Aleksi Lahti
Classifying critical points of the Euclidean Distance from real plane curves (Bachelor thesis presentation)
Wednesday 26 August 2020,   10:00,   zoom
https://aalto.zoom.us/j/69001841503

Dr Mikhail Shubin (THL)
Fitting SEIR models to COVID wave in Finland: Lessons and open questions
Thursday 25 June 2020,   15:00,   Teams
Further information
The seminar is intended for epidemiological modellers. I will present a set SEIR models used by THL to model the COVID outbreak in Finland. I will analyse particular model features, discussing whatever they there useful for inference. I will describe different questions which we tried to answer with these models, and wherever modelling was able to provide useful insight. For any questions, contact Mikhail (Mikhail.shubin@thl.fi https://teams.microsoft.com/l/meetup-join/19%3ameeting_NjE4MDVkYWUtOGQ5MS00YWIxLWIwNDYtMzUxZjQyNmExOTE5%40thread.v2/0?context=%7b%22Tid%22%3a%2281d1db0d-c492-4225-a66c-3c3a9e4b8360%22%2c%22Oid%22%3a%221373e033-bd9e-4fa9-898a-a07b58e1f61e%22%7d
Aalto Stochastics & Statistics Seminar / Leskelä

Alex Karrila (IHÉS, Paris)
Delocalization of the six-vertex height function
Thursday 11 June 2020,   10:15,   https://aalto.zoom.us/j/66281157229
The six-vertex model is a planar random model for the crystalline structure of water ice. It has recently given important insights to the connection of Conformal field theory and critical 2D random models, due to its natural representation as a random field, called the height function, and due to couplings to several other important random models (e.g. FK cluster model, Ising and Potts models, dimers, random graph homomorphisms) We prove that the six-vertex height function has a localization/delocalization phase transition. Delocalization means roughly speaking that the model is not sensitive to a boundary condition far away; indeed our result for instance implies that there exists a unique whole-plane six-vertex model in the delocalized phase. The main tools of the proof are an explicit solution of the free energy of the model, and RSW and FKG inequalities similar as in the study of various percolation models. (Based on ongoing work with Hugo Duminil-Copin, Ioan Manolescu, and Mendes Oulamara.) Zoom-link: https://aalto.zoom.us/j/66281157229
Kytölä

Dissertation
Ferdinand Blomqvist
PhD defense: On Decoding Problems, Lattices and Generalized Concatenated Codes
Wednesday 22 April 2020,   16:00,   Zoom
Further information
Link for joining the online defense: https://aalto.zoom.us/j/651995701
ANTA

Lauri Hitruhin
Convex integration and incompressible porous media equation
Wednesday 11 March 2020,   12:15,   M3 (M234)
Seminar on analysis and geometry

Chris Brzuska
Reading circle on lattices and lattice-based cryptography: on public key crypto and complexity
Wednesday 11 March 2020,   10:15,   M3 (M234)
The reading circle will gather around 10 times, check the ANTA seminar page for detailed times and talk titles.
ANTA

Dr. Hossein Mostafaei (Aalto)
Discrete- and Continuous-time Scheduling Formulations for Industrial Processes
Monday 09 March 2020,   15:15,   Y225a (Riihi)
SAL Monday seminar

Prof. Shmuel S. Oren, University of California at Berkeley
Challenges and Opportunities for OR in Electricity Markets
Friday 06 March 2020,   14:00,   M1 (M232)
Further information

Carlos Mudarra
Bounded extension operators for jets of class C^{1,w} in Hilbert spaces
Wednesday 04 March 2020,   12:15,   M3 (M234)
Seminar on analysis and geometry

Taoufiq Damir
Reading circle on lattices and lattice-based cryptography: hardness of lattice problems
Wednesday 04 March 2020,   10:15,   M3 (M234)
The reading circle will gather around 10 times, check the ANTA seminar page for detailed times and talk titles.
ANTA

Konstantin Avrachenkov (INRIA Sophia Antipolis)
Hedonic coalitional game approach to network partitioning
Monday 02 March 2020,   15:15,   M205
The traditional methods for detecting community structure in a network are based on selecting dense subgraphs inside the network. Here we propose to use the methods of coalitional game theory that highlight not only the link density but also the mechanisms of cluster formation. Specifically, we propose an approach which is based on hedonic coalitional games. This approach allows to find clusters with various resolution. Furthermore, the modularity-based approach and its generalizations as well as ratio cut and normalized cut methods can be viewed as particular cases of the hedonic games. Finally, for methods based on potential hedonic games we suggest a very efficient computational scheme using Gibbs sampling. Bio: Konstantin Avrachenkov received the master’s degree in control theory from St. Petersburg State Polytechnic University in 1996, the Ph.D. degree in mathematics from the University of South Australia in 2000, and the Habilitation (Doctor of Science) degree from the University of Nice Sophia Antipolis in 2010. Currently, K. Avrachenkov is Director of Research at Inria Sophia Antipolis. His main research interests are Markov chains, Markov decision processes, stochastic games and singular perturbations. He applies these methodological tools to the modelling and control of telecommunication systems and to design data mining and machine learning algorithms. He has won 5 best paper awards. He is an Associate Editor of the International Journal of Performance Evaluation, Probability in the Engineering and InformationalSciences, ACM TOMPECS and Stochastic Models.
Aalto Stochastics & Statistics Seminar

M.Sc. Juho Roponen (Aalto)
Protecting ship resupplying from UAV reconnaissance
Monday 02 March 2020,   15:15,   Y225a (Riihi)
SAL Monday seminar

Peter Lindqvist (NTNU)
The time derivative in some Evolutionary p-Laplace Equations: a problematic quantity
Wednesday 26 February 2020,   12:15,   M3 (M234)
Seminar on analysis and geometry

Laia Amoros
Reading circle on lattices and lattice-based cryptography: basics on lattices
Wednesday 26 February 2020,   10:15,   M3 (M234)
The reading circle will gather around 10 times, check the ANTA seminar page for detailed times and talk titles.
ANTA

Tuomas Hytönen (University of Helsinki)
Commutators and Jacobians
Tuesday 25 February 2020,   15:15,   U5
The commutator of two objects A and B is the expression AB-BA, a measure of the extent to which A and B fail to commute. Probably the most famous instance arises from the uncertainty principle in Quantum Mechanics, when A and B are the position and momentum operators, or (in a common representation of these operators) multiplication by x and differentiation in x, respectively. The commutators featuring in this talk are distant cousins of the Heisenberg commutator: again, one of the operators is multiplication by a function, while the other one is an (singular) integral operator. Among other things, such commutators have am interesting connection to a distinguished nonlinear partial differential equation, the prescribed Jacobian problem.
Department Colloquium

Kim Myyryläinen (Aalto University)
What is...Bounded Mean Oscillation (BMO)?
Tuesday 25 February 2020,   14:15,   M2 (M233)
The space of bounded mean oscillation (BMO) consists of functions whose mean oscillation over cubes is uniformly bounded. The mean oscillation tells that how much function differs in average from its integral average. One of the most important theorems concerning BMO (the John-Nirenberg inequality) states that the logarithmic blowup is the worst possible behaviour for a BMO function. It also implies that BMO is a substitute for the space of bounded functions in the sense that every BMO function is locally exponentially integrable. As one application of BMO, many interesting linear operators in harmonic analysis fail to map bounded functions to bounded functions but instead map bounded functions to BMO.
What is...? Seminar

Marti Prats
Minimizers for the thin one-phase free boundary problem (continues)
Thursday 13 February 2020,   14:15,   M235a (Tuuma)
We will give an overview of the literature on the non-negative minimizers for the one-phase free boundary problem of Alt and Caffarelli. This functional contains two competing terms, the standard Dirichlet energy and the measure of the set where the function is positive. Every minimizer is harmonic in its positive phase and vanishes elsewhere. Many questions arise regarding the regularity of the free boundary of such a minimizer, some of them still open. We will also discuss how these ideas can be brought to the thin one-phase free boundary problem, where the first term is a weighted Dirichlet energy related to the Poisson extension used to compute the fractional Laplacian, and the second competing term is only evaluated in a hyperplane. Minimizers of such a functional will have vanishing fractional Laplacian in the hyperplane's positive phase. This intrinsic nonlocallity will make some arguments to vary substantially.
Seminar on analysis and geometry

Matias Vestberg
Regularity properties of weak solutions to doubly singular equations
Wednesday 12 February 2020,   12:15,   M3 (M234)
Seminar on analysis and geometry

Alexander Engström
Standard monomials of plane partitions
Tuesday 11 February 2020,   16:15,   M2 (M233)
A set of standard monomials of an ideal gives a vector space basis for its residue ring. If the ideal is from a finite variety, then the number of points of the variety and the number of standard monomials is equal and the natural combinatorial question is to find an explicit bijection. Together with Sanyal and Stump we did that for varieties from lattice path matroid, and first I will sketch that construction. Extending from one to several lattice paths and requiring that they don't intersect constitutes a classical combinatorial object in bijection with plane partitions. There are several famous open and proved conjectures on plane partitions thanks to their presence in random matrix theory and mathematical physics. In the final part of the talk I will define the tentative monomials. They are in bijection with the plane partitions and it's proven that they have several of the properties required by standard monomials. Based on further computational evidence, I conjecture that the tentative monomials are standard monomials of plane partitions.
Algebra and discrete mathematics seminar

Dr. Lina Reichenberg (Chalmers/ Aalto University)
The Cost of Future Low-carbon Electricity System without Nuclear power in Sweden
Tuesday 11 February 2020,   13:30,   M2 (M233)
We would like to invite you for the first talk associated with the project Advanced analytics for planning future energy systems funded by the Aalto Science Institute. In this meeting, Dr. Lina Reichenberg (Chalmers/ Aalto University) will be giving a talk on The Cost of Future Low-carbon Electricity System without Nuclear power in Sweden. Her presentation will be followed by a discussion session and some coffee/ tea.
Advanced analytics for planning future energy systems

Prashanta Garain
Harnack's inequality for the fractional parabolic doubly nonlinear equation
Wednesday 05 February 2020,   12:15,   M3 (M234)
Seminar on analysis and geometry

Dario Gasbarra (University of Helsinki)
Algebraic Stein operators for Gaussian polynomial random variables
Tuesday 04 February 2020,   16:15,   M2 (M233)
For a standard Gaussian random variable N, integration by parts gives the Stein equation E(Nf(N)- Df(N))=0 The Stein equation characterizes the distribution and it is the key in proving quantitative limit theorems towards the Gaussian. Here we take the first steps in extending the methodology, and give an algorithm producing Stein differential operators with polynomial coefficients for target random variables of the form X= p(N_1, ..., N_d), with Gaussian N and polynomial p. This work is in collaboration with Ehsan Azmoodeh (Bochum) and Robert Gaunt (Manchester).
Algebra and discrete mathematics seminar

Marti Prats
Minimizers for the thin one-phase free boundary problem
Wednesday 29 January 2020,   12:15,   M3 (M234)
We will give an overview of the literature on the non-negative minimizers for the one-phase free boundary problem of Alt and Caffarelli. This functional contains two competing terms, the standard Dirichlet energy and the measure of the set where the function is positive. Every minimizer is harmonic in its positive phase and vanishes elsewhere. Many questions arise regarding the regularity of the free boundary of such a minimizer, some of them still open. We will also discuss how these ideas can be brought to the thin one-phase free boundary problem, where the first term is a weighted Dirichlet energy related to the Poisson extension used to compute the fractional Laplacian, and the second competing term is only evaluated in a hyperplane. Minimizers of such a functional will have vanishing fractional Laplacian in the hyperplane's positive phase. This intrinsic nonlocallity will make some arguments to vary substantially.
Seminar on analysis and geometry

Volker Mehrmann (TU Berlin)
Stability analysis of energy based dynamical system models
Tuesday 28 January 2020,   15:15,   U5
Dissipative port-Hamiltonian systems are an important class of models that arise in all areas of science and engineering, whenever one uses energy as the major modeling concept. Despite the fact that the model class looks very unstructured at first sight, it has remarkable algebraic and geometric properties. Systems can be coupled in a network fashion in a structure preserving way, Galerkin projection preserves the stucture. We will illustrate these and further system properties, showing for examples that stability and passivity are automatic. In the linear case Jordan structures for purely imaginary eigenvalues, eigenvalues at infinity, and even singular blocks in the Kronecker canonical form are very restricted and furthermore the structure leads to fast and efficient iterative solution methods for the associated linear systems. Motivated from an industrial application of studying brake squeal, we study questions like the spectral properties or distance to instability/stability for this system class. We use this large scale industrial finite element model to illustrate our theoretical findings with numerical computation results.
Department Colloquium

MSc. Giovanni Barbarino
What is a port-Hamiltonian System?
Tuesday 28 January 2020,   14:15,   M2 (M233)
We introduce the standard dissipative port-Hamiltonian (pH) systems through examples and basic results, giving hints on the broad variety of application areas where pH systems play a role. In the particular case of linear time-invariant systems, the spectral structure of the associated pencil can be studied through its Kronecker canonical form, that will be briefly reviewed.
What is...? Seminar

Prof. Prabhu Manyem (Nanchang Institute of Technology)
Combinatorial Optimisation: Spanning and Steiner trees, Bin Packing and Second Order Logic
Monday 27 January 2020,   15:15,   Y225a (Riihi)

Prof. Froilán M. Dopico
Sets of matrix polynomials with bounded rank and degree and their generic eigenstructures
Thursday 23 January 2020,   12:40,   M3 (M234)
Low rank perturbations of matrices, matrix pencils, and matrix polynomials appear naturally in many applications where just a few degrees of freedom of a complicated system are modified. As a consequence many papers have been published in the last 15 years on this type of problems for matrices and pencils, but just a few for matrix polynomials. A possible reason of this lack of references on low rank perturbations of matrix polynomials is that the set of matrix polynomials with bounded (low) rank and degree is not easy to describe explicitly when the rank is larger than one. The purpose of this talk is to describe such sets both in terms of its generic eigenstructures and in terms of products of two factors. We will consider unstructured matrix polynomials, as well as symmetric and skew-symmetric matrix polynomials.

Annachiara Korchmaros
Colored best match graphs
Tuesday 21 January 2020,   16:15,   M2 (M233)
In this talk we deal with a family of directed graphs, called colored best match graphs, arising from applications to evolutionary theory. We give an outline of the basic properties of such graphs and present some results in the case where their vertices are colored with two colors.
Algebra and discrete mathematics seminar

Taoufiq Damir
A Brief Introduction to the Theory of Lattices
Tuesday 14 January 2020,   16:15,   M2 (M233)
Lattices are central to number theory and discrete geometry. In addition to their arithmetic and geometric appeal, lattices are also extensively used in applied areas, such as coding theory, cryptography and other areas of digital communications. The aim of the talk is to give a gentle introduction to theory of lattices, we will start by reviewing the necessary background including relevant definitions, problems and theorems. We will then highlight some links between the theory and applications.
Algebra and discrete mathematics seminar

Quan Wang
Master thesis talk
Monday 30 December 2019,   14:00,   M305

Joni Virta (University of Turku)
Fast tensorial independent component analysis
Wednesday 18 December 2019,   16:15,   M1 (M232)
Stochastic Sauna 2019

Tom Claeys (Université Catholique de Louvain)
Random growth, interacting particles, and Riemann-Hilbert problems: from KPZ to KdV
Wednesday 18 December 2019,   15:15,   M1 (M232)
Stochastic Sauna 2019

Vesa Julin (University of Jyväskylä)
The Gaussian isoperimetric problem for symmetric sets
Wednesday 18 December 2019,   14:00,   M1 (M232)
Stochastic Sauna 2019

Jaron Sanders (TU Eindhoven)
Markov chains for error accumulation in quantum circuits
Wednesday 18 December 2019,   13:00,   M1 (M232)
Stochastic Sauna 2019

Kaie Kubjas (Aalto)
Exact solutions in log-concave maximum likelihood estimation
Wednesday 18 December 2019,   11:00,   M1 (M232)
Stochastic Sauna 2019

Teemu Pennanen (King's College London)
Convex duality in nonlinear optimal transport
Wednesday 18 December 2019,   10:00,   M1 (M232)
Stochastic Sauna 2019

Dr. Riikka Kangaslampi (Tampere University)
Introduction to hypergraphs
Tuesday 17 December 2019,   16:15,   M3 (M234)
In network science problems complex systems or datasets are often modelled as weighted graphs. These models are simple and powerful, but in some cases insufficient to capture the network structure information, if there are higher-order interactions among more than a pair of nodes. Hypergraphs are a generalisation that can be used to tackle this difficulty. In this talk I will introduce hypergraphs and some of their basic properties and provide a few examples of networks where hypergraphs would be a natural way to describe the interactions. If time permits, I will also discuss current results and research problems related to Ricci curvatures of hypergraphs.
ANTA Seminar

Prof. Norbert Peyerimhoff (Durham University)
Expander graphs and curvature
Tuesday 17 December 2019,   15:15,   M3 (M234)
Expander graphs are increasing families of graphs which are at the same time sparse and very well connected. They are not only of practical relevance for the construction of robust networks but their theoretical research uncovered many suprising connections with various mathematical disciplines: representation theory (Kazdhan property (T)), geometric group theory (Cayley graphs), combinatorics (zigzag products), number theory (Ramanujan graphs), spectral theory (Cheeger inequalities) and probability theory (random walks and random covers). Another challenging question about graphs are to introduce proper notions of curvature. In this talk, I will briefly present an analytical approach, due to Bakry-Emery, which allows to define curvature on graphs. Once these concepts are introduced, I will discuss relations between expander graphs and Bakry-Emery curvature.
ANTA Seminar

Camilla Hollanti and Ellie Dillon
Mentoring breakfast
Tuesday 10 December 2019,   09:30,   M-wing common room
Information about department’s mentoring program. Please join if you are interested in being a mentor or getting one, or just hearing a bit more about mentoring in general.

Sami Helander (Aalto)
On Adaptive functional data depths
Monday 09 December 2019,   14:15,   Y313
Typically, in the functional context, data depth approaches heavily emphasize the location of the functions in the distribution, therefore often missing important shape or roughness features. Commonly, these depth approaches either integrate pointwise depth values to achieve a global value, or measure the expected distance from a function to the distribution. In this talk, we introduce a new class of functional depths, based on the distribution of depth values along the domain, and discuss their properties. We study the asymptotic properties of these $J$th order $k$th moment integrated depths, and illustrate their usefulness in supervised functional classification. In particular, we demonstrate the importance of receptivity to shape variations, and show that, similarly to existing depth notions, the new class of depth functions takes into account the variation in location, while remaining receptive to variations in shape and roughness.
Aalto Stochastics and Statistics seminar

Elias Jäämeri
MSc thesis presentation: On code-based cryptography
Wednesday 04 December 2019,   15:15,   M3 (M234)
ANTA Seminar

Tommi Summanen
Karkeiden stokastisten osittaisdifferentiaaliyhtälöiden diskretoinnista (kandiesitelmä)
Wednesday 04 December 2019,   15:15,   Tuuma (M235a)

Emma-Karoliina Kurki
Extension results for Muckenhoupt weights
Wednesday 04 December 2019,   12:15,   M3 (M234)
Seminar on analysis and geometry

Toni Annala (University of British Columbia)
Deriving intersection theory and algebraic cobordism
Tuesday 03 December 2019,   16:15,   M2 (M233)
I will quickly introduce intersection theory and algebraic cobordism and recall some foundational difficulties in the subject. I will then outline how derived algebraic geometry, introduced by Toën-Vezzosi and Lurie, can be used to overcome many of these difficulties. Finally, I will outline the current state of the art understanding of these new ``derived'' cohomology theories. The talk is partly based on joint work with Shoji Yokura.
Algebra and Discrete Mathematics Seminar

Muhammad Ardiyansyah (Aalto)
Introduction to Phylogenetic Algebraic Geometry
Tuesday 03 December 2019,   15:15,   M2 (M233)
Phylogenetics is the study of how various organisms are related, and is very closely related to taxonomy, the classification of organisms. This relationships are usually decribed using evolutionary trees, which will be our basic objects. We will view this topics from algebraic viewpoint. We will introduce some basic models on phylogenetics. By “phylogenetic algebraic geometry” we mean the study of algebraic varieties which represent models of evolution. In fact, under many standard models of molecular evolution (for example, DNA sequences), for a fixed tree topology, the joint distribution of bases at the leaves are described by polynomial equations in the parameters of the model. This fact lead us to search for polynomials, called phylogenetic invariants, which vanish on any joint distribution arising from the tree and model, regardless of parameter values.
Algebra and Discrete Mathematics Seminar

Paavo Raittinen (Aalto)
On early detection of high-risk prostate cancer: applied discovery and validation models using genotype information
Monday 02 December 2019,   14:15,   Y313
Prostate cancer incidence rate is extremely high and on the rise, counting over 1.2 million new cases annually and causing 350 000 deaths in 2018. While the prognosis is typically good, approximately 20% of the new cases classifies as high-risk prostate cancer with dire consequences. Moreover, the initial prostate cancer diagnosis always reflects as worry and quality of life impairment. The initial prostate cancer determination is based on prostate specific antigen (PSA) measure, which cannot distinguish between low-risk and high-risk cases. After the PSA determination, the tumor state is characterized with various invasive methods such as Gleason score and T-stage classification. However, both methods display inaccuracy and puts patient under infection risk. Our take on this challenge is to use inflammation-related gene single nucleotide polymorphisms (SNP) as predictors of high-risk prostate cancer. SNP is a low-cost, non-invasive, and stable biomarker. We have explored inflammation SNP association with high-risk prostate cancer in a genotyped part of Finnish Randomized Screening for Prostate Cancer cohort (n = 2715) and found several statistically significant associations. Furthermore, our validation model using unknown prostate cancer cohort collected during hospital visits (n = 888) is in concordance with our discovery model. Remarkably, few SNPs increase early high-risk prostate cancer detection over PSA alone.
Aalto Stochastics and Statistics seminar

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