IWR-Colloquium Wintersemester 2017 / 2018  • Vortragsreihe Didaktik

"Den mathematischen Blick öffnen - forschendes und dialogisches Lernen im Mathematikunterricht"

Prof. Dr. Brigitte Lutz-Westphal • Freie Universität Berlin
13. Dezember 2017 • 16:15

Wo gibt es Mathematik zu entdecken? Wie kann der aktive und neugierige mathematische Blick von Lernenden gestärkt und erweitert werden? Dialogisches und forschendes Lernen sind zwei Ansätze für den Mathematikunterricht, die den individuellen Fragen, Ansätzen und Erarbeitungswegen der Lernenden Raum geben. Gleichzeitig gelingt es, ausgehend von alltäglichen, ja oft sogar eher banal erscheinenden Fragestellungen tiefergehend mathematisch zu arbeiten. Sehr häufig kommt man dabei sogar auf aktuelle mathematische Forschungsfragen. Nicht einfach ist die Frage, wie forschendes Lernen im Fach Mathematik überhaupt authentisch gestaltet werden kann. Es wird über aktuelle Forschung sowie über Erfahrungen aus der Lehramtsausbildung und der wissenschaftlichen Begleitung des Programms „Mathe.Forscher“ der Stiftung Rechnen berichtet. Der Vortrag bietet konkrete Unterrichtsideen und Anregungen für den Unterricht in den Sekundarstufen.

Veranstaltungsort: Mathematikon • Konferenzraum / 5. Stock • Im Neuenheimer Feld 205 • 69120 Heidelberg

Compact Course

"Computational Methods and Strategies in Structure-Based Drug Design"

Joanna Panecka-Hofman, Daria Kokh, Neil Bruce
December 4-5, 2017 

This course will present principles of simulation methods applicable in structure-based drug design
and practical aspects of structure-based drug design strategies. We will focus on such techniques
as ligand docking, molecular dynamics and binding free energy estimation methods.

• Lead design strategies with examples
• Force fields and interaction fields
• Binding site identification, mapping and comparison
• Ligand docking methods with examples
• Thermodynamics vs. kinetics
• Molecular dynamics and enhanced sampling in drug design

!Attention! Limited number of participants, registration required, please register here.

Location: Mathematikon • Seminar Room 12 / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

IWR Colloquium Winter Term 2017 / 2018

"Uncertainty Quantification: Mathematical and Computational Aspects"

Prof. Elisabeth Ullmann • Technical University of Munich
November 15, 2017 • 16:15

Uncertainty quantification (UQ) is a fast growing research area which deals with the impact of parameter, data and model uncertainties in complex systems. We focus on models which are based on partial differential equations (PDEs) with random inputs. For deterministic PDEs there are many classical analytical results and numerical tools available. The treatment of PDEs with random inputs, however, requires novel ideas and tools. We illustrate the mathematical and algorithmic challenges of UQ for Bayesian inverse problems arising from geotechnical engineering and medicine, and an optimal control problem with uncertain PDE constraints.

This talk is also part of the HGS MathComp Ladyzhenskaya Lecture Series.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

Talk / Special Interest Group “Mathematics of Life”

"Fixation Probabilities under Demographic Fluctuations"

Dr. Peter Czuppon • Max Planck Institute for Evolutionary Biology
November 9, 2017 • 16:00

We consider a population consisting of two species. Each type gives birth and dies independently of the other one. Population size is regulated by intra- and interspecific competition events letting the model follow generalized Lotka-Volterra dynamics. A quantity of interest in finite populations is the probability of fixation/extinction of one type. While it has been studied broadly in the context of fixed or deterministically varying population sizes we approximate the fixation probability in populations with stochastically fluctuating sizes. In order to do so we will take the limit of weak selection, i.e. the "fitness" benefit of one type over the other is very small.

“Mathematics of Life” is a special interest group organized by doctoral students of the HGS MathComp.

Location: Bioquant • SR 043 • Im Neuenheimer Feld 267 • 69120 Heidelberg

IWR School

"Mathematical Methods for Quantum Chemistry"

October 2-6, 2017 • Heidelberg, Germany

The IWR school 2017 "Mathematical Methods for Quantum Chemistry" targets young researchers from both the field of mathematics and of computational chemistry. Starting with formal basic introductions into both fields to level the ground and introduce the leading concepts and models, the school quickly turns to key aspects of computational quantum chemistry. It analyzes the structure of the underlying eigenvalue problems and outlines and describes in detail numerical concepts of modern algorithmic approaches to deal with these problems in an efficient and error-controlled way. It then turns to basis set representations to open the view into the interplay between mathematical representation, computational treatment and research in quantum chemistry. The theoretical lectures are complemented by hands-on sessions to enable practitioners to make use of modern computation facilities for fast solution of large problems.

The training program is taught in a series of short courses by:

• Eric Cancès, Ecole des Ponts Paris Tech and INRIA Paris
• Denis Davydov, FAU Erlangen-Nürnberg
• Andreas Dreuw, Heidelberg University
• Guido Kanschat, Heidelberg University
• Katharina Kormann, Max Planck Institute for Plasma Physics
• Reinhold Schneider, TU Berlin

Location: Mathematikon • Im Neuenheimer Feld 205 · 69120 Heidelberg

ZUK 5.4

ArchEyeAutomatic Summer School 2017: "Cameras, Drones, and Laser scanning - Modern ways to document ancient objects"

Christian Seitz • Katja Mombaur • Matthias Untermann
July 26-28, 2017

Digital documentation and preservation is a key knowledge for archaeologists, no matter in which research area they are working in. This summer school gives a short introduction in the main digital methods currently used along with practical experience in real environments producing real data. The methods we want to show you are broad:

• Structure from motion: This method uses a series of images to create 3D models. Can be used for small finds to whole buildings (with drones)
• Drones: With drones, Structure from motion can acquire whole buildings or even landscapes. Several methods, from fixed wing (small airplanes) to multirotor drones will be shown.
• Laser scanning: This device can create high precision point clouds in very short time and is very useful for all kind of documentation tasks.
• Structured light scanner: This device is especially suited for small finds and objects. It projects actively light on the object to detect surfaces. The precision and quality is very high.
• David scanner: A low-budget version of the Structured Light Scanner using laser beams. The results are very good.
• Ground Penetrating Radar: Makes structures in the earth visible without excavating. One of the so called “non invasive methods”
• Analysis of airborne LiDAR: Covering large areas, airborne LiDAR can help to detect a lot of archaeological remains, even in forested areas.
• Geographic Information Systems: With the help of Geographic information systems, the analysis of historic movements, distribution systems and many more became possible.

Further inquiries: cdl2017@iwr.uni-heidelberg.de

Location: UNESCO-Welterbe Kloster Lorsch • Nibelungenstraße 32 • 64653 Lorsch

Interdisciplinary Seminar Series "Structures & Mathematics"

"The quest for the wiring diagram of the brain - Where computer vision, deep neural networks and combinatorial optimization meet"

Prof. Fred Hamprecht • Heidelberg University
July 20, 2017 • 12:00

Understanding the brain is an old and yet-unsolved problem. To understand the workings of a neural circuit, it is possibly required to know its structure, and almost surely necessary to know its connectivity.

After great progress in electron microscopy, several labs worldwide are milling away at animal brains and generating what will amount to petabytes of high-quality data. The resulting images are good enough for human tracers to consistently follow at least the majority of neural processes; unfortunately, humans would take thousands of years to complete the task for even the smallest mammalian brain.

So the quest is on for computer vision algorithms to do the same automatically and reliably. The current state of the art pipelines recur to deep neural networks and combinatorial graph partitioning problems. The former are notoriously ill understood, the latter still expensive to solve at scale.

In this talk, I will sketch the problem, a state of the art approach (which does not quite achieve human accuracy yet), and I will lay out some of the open problems in the field.

Interdisciplinary Seminar Series "Structures & Mathematics":

The workshop-seminars aim at initiating interactions between mathematicians and researchers from other sciences. We want to explore in particular questions and problems, which might be of interest to and benefit from the involvement of mathematicians of all sort. The setting of the seminar is informal, and interactive.

Link: Homepage "Structures & Mathematics"

Location: Kirchhoff-Institute for Physics • Lecture Hall 2 • Im Neuenheimer Feld 227 • 69120 Heidelberg

Tag der Offenen Tür

"Mathematik, Informatik und Scientific Computing zum Anfassen"

IWR & Fakultät für Mathematik und Informatik
8. Juli 2017 • 10:00 bis 16:00 Uhr

Am 8. Juli laden die Fakultät für Mathematik & Informatik und das Interdisziplinäre Zentrum für Wissenschaftliches Rechnen (IWR) gemeinsam zum Tag der Offenen Tür im Mathematikon der Universität Heidelberg ein. Von Mathematik zum Anfassen über Forschung zu Künstlicher Intelligenz bis zum Robotiklehrlabor - Wissenschaftler geben spannende Einblicke in die Forschung und Praxis rund um Mathematik, Informatik und Scientific Computing. Führungen durch eines der neuesten Gebäude der Universität Heidelberg ergänzen das abwechslungsreiche Programm.Eine Auswahl an Speisen und Getränken wird durch die Fachschaft MathPhys angeboten.Der Eintritt ist frei.

Veranstaltungsort: Mathematikon • Im Neuenheimer Feld 205 • 69120 Heidelberg

International Workshop

"Fast High Order DG Methods for Future Architectures"

Sponsored by DFG Priority Programme 1648 SPPEXA
July 3-5, 2017

The joint workshop of the EXA-DUNE, EXAMAG and ExaDG projects, being part of the DFG Priority Programme Software for Exascale Computing (SPPEXA), will take place at the Mathematikon in Heidelberg, Germany. The event will be hosted collaboratively by the Heidelberg Institute for Theoretical Studies (HITS) and Heidelberg University's Interdisciplinary Center for Scientific Computing (IWR).The workshop provides a discussion venue for mathematical and algorithmic problems arising when implementing fast, parallel solvers for high-order DG discretizations of PDE problems. Key aspects are

• considering how to exploit tensorial structures to reduce the complexity of local cell and face integral evaluation within a matrix-free based code,
• using algebraic multigrid methods in a computationally intensive framework,
• an implementation of efficient cell- and patch-based smoothers for geometric multigrid methods applicable in a massively parallel environment,
• data locality and
• heterogeneous parallelism, e.g. as when computing boundary and volume integrals simultaneously.

In particular, the algorithms above and mathematical models are discussed with regard to their enhancement of performance and scalability by employing hybrid parallelization techniques, namely multithreading and message passing, combined with low-level optimizations that make full use of vector instructions and device accelerators.

Location: Mathematikon • Im Neuenheimer Feld 205 • 69120 Heidelberg

13. Modellierungstag Rhein-Neckar

"Stadt, Technik, Natur - Am Anfang steht das Modell"

22. Juni 2017 • 14:00 Uhr

Moderne Infrastruktur bestimmt unser Leben und beeinflusst in entscheidender Weise Arbeitsprozesse. Der Industriestandort Deutschland profitiert von seiner idealen Lage im Herzen Europas ebenso wie von Verfügbarkeit und Erreichbarkeit, von Netzkapazitäten oder stadtnahen Produktionsflächen.Unsere Städte spielen in dieser Konstellation eine bedeutende Rolle und ihr Funktionieren hängt maßgeblich von modellbasierter Planung in allen Bereichen ab: Stadtentwicklung, Straßenbau, intelligente Vernetzung und Breitbandversorgung. Diese komplexen Prozesse basieren auf individuellen Modellen, um Systemkomponenten zu erfassen, ihre Veränderung anhand von Simulationen zu planen und Abläufe zu optimieren.Die Stellung Deutschlands als Wirtschaftsstandort erfolgreicher Industrieunternehmen und als Lebensmittelpunkt von über 80 Millionen Menschen hängt vom effizienten, exakten und adäquaten Einsatz moderner Modelle ab. Im Wettbewerb der Besten bietet das den vielleicht entscheidenden Standortvorteil für deutsche Unternehmen – gerade auch im Bereich der KMUs, die seit vielen Jahren vom Funktionieren dieser Infrastruktur international profitieren.Alle Prozesse rund um die Planung in Stadt und Land sind das Thema des 13. Modellierungstags. Gemeinsam besprechen wir neueste Trends aus der Praxis, schauen den planerisch tätigen Wissenschaftlern über die Schulter und diskutieren die Entwicklungen von morgen.

Die Veranstaltung ist öffentlich. Die Teilnahme ist kostenfrei. Um Anmeldung unter www.modellierungstag.de wird gebeten.

Veranstaltungsort: Mathematikon • Konferenzraum (5. Stock) • Im Neuenheimer Feld 205 • 69120 Heidelberg

IWR-Colloquium Summer Term 2017

"What is Non-Linear Preconditioning?"

Prof. Martin Gander • University of Geneva (UNIGE), Switzerland
June 21, 2017 • 14:15

The idea of preconditioning iterative methods for the solution of linear systems goes back to Jacobi (1845), who used rotations to obtain a system with more diagonal dominance, before he applied what is now called Jacobi’s method. The preconditioning of linear systems for their solution by Krylov methods has become a major field of research over the past decades, and there are two main approaches for constructing preconditioners: either one has very good intuition and can propose directly a preconditioner which leads to a favorable spectrum of the preconditioned system, or one uses the splitting matrix of an effective stationary iterative method like multigrid or domain decomposition as the preconditioner.

Much less is known about the preconditioning of non-linear systems of equations. The standard iterative solver in that case is Newton's method (1671) or a variant thereof, but what would it mean to precondition the non-linear problem? An important contribution in this field is ASPIN (Additive Schwarz Preconditioned Inexact Newton) by Cai and Keyes (2002), where the authors use their intuition about domain decomposition methods to propose a transformation of the non-linear equations before solving them by an inexact Newton method. Using the relation between stationary iterative methods and preconditioning for linear systems, we show in this presentation how one can systematically obtain a non-linear preconditioner from classical fixed point iterations, and present as an example a new two level non-linear preconditioner called RASPEN (Restricted Additive Schwarz Preconditioned Exact Newton) with substantially improved convergence properties compared to ASPIN.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

Talk / Special Interest Group “Mathematics of Life”

"Modelling glioma growth with fully anisotropic diffusion"

Prof. Thomas Hillen • University of Alberta, Canada
June 6, 2017 • 11:00

The human brain has a complex geometric structure consisting of white and gray matter, blood vessels, ventricles, skull etc. It forms a highly anisotropic medium. Glioma in the brain are known to invade along white matter tracks and along other brain structures. Using diffusion tensor imaging (DTI) it is now possible to obtain directional information of the brain geometry. In my talk I will show how this DTI information can be used to parametrize a fully anisotropic diffusion equation for glioma spread. We validate the model on clinical data of glioma patients and discuss the future use in treatment design. (joint work with A. Swan, K.J. Painter, C. Surulescu, C. Engwer, M. Knappitsch, A. Murtha).

Followed by: “Meet the speaker” in the common room (with drinks and canapes)

“Mathematics of Life” is a special interest group organized by doctoral students of the HGS MathComp.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

IWR-Colloquium Summer Term 2017

"Deep Learning with Dense Connectivity"

Prof. Kilian Weinberger • Cornell University, USA
May 31, 2017 • 16:15

Although half a decade has passed since Frank Rosenblatt’s original work on multi-layer perceptrons, modern artificial neural networks are still surprisingly similar to his original ideas. In this talk I will give a brief introduction on deep neural networks and will question one of their most fundamental design aspects. As networks have become much deeper than had been possible or had even been imagined in the 1950s, it is no longer clear that the layer by layer connectivity pattern is a well-suited architectural choice.
In the first part of the talk I will show that randomly removing layers during training can speed up the training process, make it more robust, and ultimately lead to better generalization. We refer to this process as learning with stochastic depth -- as the effective depth of the networks varies for each minibatch.
In the second part of the talk I will propose an alternative connectivity pattern, Dense Connectivity, which is inspired by the insights obtained from stochastic depth. Dense connectivity leads to substantial reductions in parameter sizes, faster convergence, and further improvement in generalization. Finally, I will show examples of problems that were considered challenging but have become surprisingly easy in the light of deep learning.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

IWR-Colloquium Summer Term 2017

"Digital Humanities - Shaping New Avenues of Scholarly Research"

Prof. Heather Richards-Rissetto • University of Nebraska-Lincoln, USA
May 10, 2017 • 16:15

The Center for Digital Research in the Humanities (CDRH) at the University of Nebraska-Lincoln (UNL) - founded in 2005 - was one of the earliest Digital Humanities (DH) centers in the world, and is supported by the University as a Center of Excellence as well as by private funds and grants. The Center is a founding member of centerNet, an international network of digital humanities centers, and is an institutional member of the TEI Consortium, the National Humanities Alliance, and the National Humanities Alliance. While the Center’s roots are in Library Science and English, the mission of CDRH is to promote collaborative and transdisciplinary digital humanities research. The Center houses over fifty scholarly projects ranging in scale, topic, and purpose. In the first part of the talk, I will present an overview of these diverse projects, some of their challenges, and their wide-spread impact in the humanities and beyond.

In the second half, I will focus specifically on Digital Cultural Heritage (DCH). Recent DH cluster hires in Anthropology, Classics & Religious Studies, History, and Art & Art History at UNL are facilitating innovative research in DCH. In particular, CDRH scholars are applying and developing Geographic Information Systems (GIS), 3D Modeling, and Virtual Reality (VR) methods and tools to foster new avenues of scholarly research. Underlying much of this research is the need to unite quantitative and qualitative data—requiring new computational methods and 3DGIS tools. I will present some of my experiences, outcomes, and ongoing challenges for three DCH projects — MayaArch3D (2009-2015), MayaCityBuilder (2016-present), and Keeping Data Alive (2017-present) - situating them within the larger framework of Digital Humanities.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

IWR-Colloquium Summer Term 2017

"Swarming, Interaction Energies and PDEs"

Prof. José A. Carrillo de la Plata • Imperial College London, UK
May 5, 2017 • 14:15

I will present a survey of the main results about first and second order models of swarming where repulsion and attraction are modeled through pairwise potentials. We will mainly focus on the stability of the fascinating patterns that you get by random particle simulations, flocks and mills, and their qualitative behavior. Qualitative properties of local minimizers of the interaction energies are crucial in order to understand these complex behaviors. Compactly supported global minimizers determine the flock patterns whose existence is related to the classical H-stability in statistical mechanics and the classical obstacle problem for differential operators.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

Seminar

"Nuclear Shape, ELCS and Epichromatin"

Prof. Donald E. Olins & Prof. Ada Levy Olins • University of New England, USA
April 24, 2017 • 16:15

Cell nuclei are not always spherical; some are highly irregular. The structural basis for this multiplicity of shapes appears to derive from the components of the nuclear envelope and their interactions with cytoskeletal elements. Describing these shapes mathematically is a challenge; explaining their biochemical origin remains a mystery. The goal of this seminar is to discuss aspects of these problems and to provoke comments and ideas from the audience.

Website Prof. Donald E. Olins

Website Prof. Ada Levy Olins

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

Talk

"Analytical approximations for spatial stochastic gene expression in single cells and tissue"

Dr. Ramon Grima • University of Edinburgh, UK
March 8, 2017 • 11:00

Gene expression occurs in an environment in which both stochastic and diffusive effects are significant. Spatial stochastic simulations are computationally expensive compared to their deterministic counterparts and hence little is currently known of the significance of intrinsic noise in a spatial setting. I will show how starting from the reaction-diffusion master equation (RDME) describing stochastic reaction-diffusion processes, we can derive closed-form expressions for the approximate steady-state mean concentrations which are explicit functions of the dimensionality of space, rate constants and diffusion coefficients. These are generally different from those given by the deterministic theory of reaction-diffusion processes, thus highlighting the importance of intrinsic noise. Our theory is confirmed by comparison with stochastic simulations, using the RDME and Brownian dynamics, of two models of stochastic and spatial gene expression in single cells and tissues. Lastly, time permitting, I will discuss how one can extend these results to stochastic spatial simulations of intracellular processes which take into account macromolecular crowding, namely the volume exclusion due to the finite size of molecules.

Discussion with the speaker after the talk (at around 12:00), coffee will be provided.

Location: Mathematikon • Lecture Hall (Room 00.005) / Ground Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

ZUK 5.4 Workshop

"CAA17 - Computeranwendungen und Quantitative Methoden in der Archäologie"

10. - 11. Februar 2017

Themen:

• Technologien von 3D-Laserscan-Verfahren bis hin zu Archäoinformationssystemen
• Interdisziplinäre Verbindung von Archäologie und wissenschaftlichem Rechnen
• Methoden zur computergestützten Analyse archäologischer Befunde
• Einfluss von Open Access und Verbindungen mit Open Data
• Perspektiven der Lehre und Nachwuchsförderung 

Keynote:

• Prof. Reinhard Förtsch, Deutsches Archäologisches Institut (DAI)

Gemeinsame Veranstaltung der AG Computer-Anwendungen und Quantitative Methoden in der Archäologie (CAA) und des Zukunftskonzepts der Universität Heidelberg – Massnahme 5.4 „Wissenschaftliches Rechnen“.

Veranstaltungsort: Mathematikon • Seminarräume A+B & Hörsaal • Im Neuenheimer Feld 205 · 69120 Heidelberg

IWR-Colloquium Winter Term 2016 / 2017

"Music Information Retrieval - When Music meets Computer Science"

Prof. Meinard Müller • International Audio Laboratories Erlangen (AudioLabs), Fraunhofer IIS & Friedrich-Alexander-Universität Erlangen-Nürnberg
February 1, 2017 • 16:15

Significant digitization efforts have resulted in large music collections, which comprise music-related documents of various types and formats including text, symbolic data, audio, image, and video. In the field of music information retrieval (MIR) great efforts are directed towards the development of technologies that allow users to access and explore music in all its different facets. For example, during playback of some CD recording, a digital music player may present the corresponding musical score while highlighting the current playback position within the score. On demand, additional information about melodic and harmonic progression or rhythm and tempo is automatically presented to the listener. A suitable user interface displays the musical structure of the current piece of music and allows the user to directly jump to any key part within the recording without tedious fast-forwarding and rewinding. In this talk, I discuss a number of current research problems in the field of music information retrieval and indicate possible solutions. One fundamental problem is to decompose a given music signal into semantically meaningful components. To guide the decomposition, one may exploit additional information, either in the form of specific acoustic properties of the components or in the form of additional score information. As an example, I show how to compute a notewise decomposition of a music signal by applying a score-informed variant of non-negative matrix factorization (NMF). Finally, I discuss various audio editing and manipulating applications to highlight the potential of these decomposition techniques.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg

IWR-Colloquium Winter Term 2016 / 2017

"Finite dimensional state representation of linear and nonlinear delay systems"

Prof. Mats Gyllenberg • University of Helsinki, Finland
January 11, 2017 • 16:15

We consider the question of when delay systems, which are intrinsically infinite dimensional, can be represented by finite dimensional systems. Specifically, we give conditions for when all the information about the solutions of the delay system can be obtained from the solutions of a finite system of ordinary differential equations. For linear autonomous systems and linear systems with time-dependent input we give necessary and sufficient conditions and in the nonlinear case we give sufficient conditions. The ideas and results are illustrated by models for infectious diseases and physiologically structured populations.

Location: Mathematikon • Conference Room / 5th Floor • Im Neuenheimer Feld 205 • 69120 Heidelberg