Alexey Kuznetsov

Evgeny Spodarev

Kirstin Strokorb

### On the spectral properties of tangent vector fields on surfaces with applications to geometry processing

Mirela Ben-Chen
Tangent vector fields on surfaces are linear operators acting on scalar functions. Taking this classical view as the starting point for the discretization of tangent vector fields on discrete surfaces, leads to interesting operator-based insights and applications. For example, geometric properties of the vector field can be expressed as algebraic properties of its matrix representation. We will present some theoretical properties and applications to geometry processing.

### Eigenvalue asymptotics for Steklov-type problems on curvilinear polygons

David Sher
We study eigenvalue asymptotics for a class of Steklov problems, possibly mixed with Dirichlet and/or Neumann boundary conditions, on planar domains with piecewise smooth boundary and with finitely many corners. This includes the famous "sloshing problem" as well as the Steklov problem on polygons. Two interesting features of this problem, which I will explain, are the surprisingly precise asymptotics we can obtain (with error decreasing as the spectral parameter increases) and a connection to a...

### Spectral Matching - Application to Brain Surfaces

Hervé Lombaert
How to analyze complex shapes, such as of the highly folded surface of the brain This talk will show how spectral representations of shapes can benefit neuroimaging. Here, we exploit spectral coordinates derived from the eigenfunctions of the graph Laplacian. Methodologically, we address the inherent instability of spectral shape decompositions. This change of paradigm, exploiting spectral representations, enables an intrinsic processing of brain surfaces. Brain surface matching will be shown as an example.

### Diffusion generated methods for target-valued maps

Braxton Osting
A variety of tasks in inverse problems and data analysis can be formulated as the variational problem of minimizing the Dirichlet energy of a function that takes values in a certain target set and possibly satisfies additional constraints. These additional constraints may be used to enforce fidelity to data or other structural constraints arising in the particular problem considered. I'll present diffusion generated methods for solving this problem for a wide class of target sets...

### Unconditionally Stable CutFEM for Dynamic Interfaces in a Fluid Structure Interaction Problem

Marcus Sarkis
Interface problems arise in several applications including heart models, cochlea models, aquatic animal locomotion, blood cell motion, front-tracking in porous media flows and material science, to name a few. One of the difficulties in these problems is that solutions are normally not smooth across interfaces, and therefore standard numerical methods will lose accuracy near the interface unless the meshes align to it. However, it is advantageous to have meshes that do not align with the...

### FSI: from the Immersed Boundary Method to a Fictitious Domain approach with Lagrange multiplier

Daniele Boffi
In this talk we discuss the finite element approximation of fluid-structure interaction problems. After presenting a finite element version of the Immersed Boundary Method (originally developed by Peskin in the finite difference framework), we show how the introduction of a distributed Lagrange multiplier allows the design of a Fictitious Domain formulation. The properties of our approach include a superior mass conservation, unconditional stability for the time discretization, and rigorous convergence analysis for the steady state...

### Energy-based methods for time-dependent acoustic and elastic wave propagation

Jesse Chan
Weight-adjusted inner products are easily invertible approximations to weighted L2 inner products and mass matrices. These approximations make it possible to formulate very simple time-domain discontinuous Galerkin (DG) discretizations for wave propagation based on the the energy of the system. The resulting methods are low storage, energy stable, and high-order accurate for acoustic and elastic wave propagation in arbitrary heterogeneous media and curvilinear meshes. We conclude with numerical results confirming the stability and high-order accuracy...

William Bement

### Markov generators of stochastic limit type

Luigi Accardi
I will introduce some general properties of the generators mentioned in the title. This general properties will be illustrated in the case of low density type generators in the talk by Fernando Guerrero-Poblete

### Bures distance for completely positive maps

B V Rajarama Bhat
D. Bures defined a metric on states of a C*-algebra as the infimum of the distance between associated vectors in common GNS representations. Now there are modifications and extensions of this notion to completely positive maps. We present some recent results in the area. This is based on joint works with K. Sumesh and Mithun Mukherjee.

### Heat kernels and functional inequalities on generalized diamond fractals

Patricia Alonso-Ruiz
Generalized diamond fractals constitute a parametric family of spaces that arise as scaling limits of so-called diamond hierarchical lattices. The latter appear in the physics literature in the study of random polymers, Ising and Potts models among others. In the case of constant parameters, diamond fractals are self-similar sets. This property was exploited in earlier investigations by Hambly and Kumagai to study the corresponding diffusion process and its heat kernel. These questions are of interest...

Qi Feng

### Quantum character varieties and $q$-Askey scheme

Marta Mazzocco
The Askeyâ Wilson polynomials are a special case of Macdonald polynomials; their degenerations are organised into a hierarchy called $q$-Askey scheme. In this talk the speaker will give a new approach to study degenerations as well as dualities in the $q$-Askey scheme, based on the fact that all families of polynomials in the $q$-Askey scheme admit a certain algebra of symmetries (the Zhedanov algebra and its degenerations) and in the limit as $q\to 1$ this...

### Bounds for the distinguishing index of finite graphs

Rafal Kalinowski
The distinguishing index $D'(G)$ of a graph $G$ is the least number of colours in an edge colouring that breaks all nontrivial automorphisms of $G$. This invariant is defined only for graphs with at most one isolated vertex and without $K_2$ as a component (we call them admissible graphs). The general upper bound for connected admissible graphs is $D'(G)\leq \Delta(G)$ except for small cycles $C_3,C_4,C_5$. Moreover, it was proved by the second author that the...

### Algebraic groups with good reduction and unramified cohomology

Igor Rapinchuk
Let $G$ be an absolutely almost simple algebraic group over a field $K$, which we assume to be equipped with a natural set $V$ of discrete valuations. In this talk, our focus will be on the $K$-forms of $G$ that have good reduction at all $v$ in $V$ . When $K$ is the fraction field of a Dedekind domain, a similar question was considered by G. Harder; the case where $K=\mathbb{Q}$ and $V$ is the...

### On the distinguishing number of locally finite trees

Svenja Hüning
The distinguishing number $D(G)$ of a graph $G$ is the smallest number of colors we need to color the vertices of $G$ such that the only color-preserving automorphism on $G$ is the identity. We are interested in the distinguishing number of locally finite trees. Our work is motivated by the "Infinite Motion Conjecture" given by Tucker in 2011. It says that $D(G) = 2$ if every non-identity automorphism of a given connected, locally finite, infinite...

### A view of uncountable graphs

Wilfried Imrich
Many results on distinguishing finite and locally finite graphs have easy extensions to graphs without degree restrictions or to uncountable graphs. Some other results are very difficult to generalize, and many hopelessly difficult. The talk presents a selection of results and problems for graphs without degree restrictions or uncountable graphs, and how they relate to the locally finite case. It concludes with challenging, interesting problems.

### Outgoing

File contains copies of outgoing executive correspondence dated April 29, 1980 to December 18, 1980. Topics include strike notice, collective agreement interpretation, strike fund assessment deductions, strikebreakers, union representatives and representation, bonuses, cutbacks, affiliation, relationship with the Provincial, office relocation and administration, funding cuts of the AMS Women's Office, the University Detachment of the RCMP, cooperation with other unions, and membership dues. Recipients consist of UBC officials and employees.

### Removal of natural organic matter for drinking water treatment using electrocoagulation and ultrafiltration

Emily Froese
This work combined iron electrocoagulation (EC) and ultrafiltration (UF) to treat synthetic and natural surface waters to remove Natural Organic Matter (NOM). Fixed EC conditions were applied to the feed water in a continuous flow EC reactor, at a flow rate of 1 LPM and an applied current of 2 A. These test conditions resulted in an average DOC and UVA-254 reduction of 33+/-4% and 57+/-8% respectively for the synthetic feed water. The EC effluent...

### Normative worlds clashing : state planning, indigenous self-determination, and the possibilities of legal pluralism in Chile

Magdalena Ugarte Urzua
Much of the history of Indigenous-state relations in Chile has been shaped by western understandings of law, and by Indigenous engagement with and opposition to such understandings. Spanish colonial law was used to justify settler presence, land dispossession, and violence. Independence was supported by the imposition of Chile’s newly created legal system upon pre-existing Indigenous nations, legitimating territorial annexation and nation building from the state’s standpoint. Today, the state interacts with Indigenous peoples through the...

### Investigating effects of contextualized science curricular experiences on students’ learning and their teachers’ teaching in Tanzania

Winston Edward Massam
This study investigated the effects of contextualized science curricular experiences on students’ learning and their teachers’ teaching in a Tanzanian context. One hundred and eighty (180) students from a select secondary school participated in an 8-months science curriculum with at least one contextualized science lesson occurring once a week. Data was collected from May to December 2013 through mixed methods techniques. Descriptive statistics, principal component, and confirmatory factor analyses constituted the quantitative analytical methods. These...

### Fraser River Highway : The Only Route for Provincial Highway

"Reasons for choosing the Fraser River route for the provincial highway."-- Edwards, M. H., Lort, J. C. R., & Carmichael, W. J. (1975). A bibliography of British Columbia: Years of growth, 1900-1950. Victoria, BC: University of Victoria, p. 39

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