uk: Математика, природничі науки

description: For a compact Lie group action on a smooth manifold, we will introduce a complex of basic relative forms on the inertia space, which was originally constructed by Brylinski. We will explain how basic relative forms can be used to study the Hochschild homology of the convolution algebra. This is work in progress with Markus Pflaum and Hessel Posthuma.

uk: вхід без авторизації

name: Hochschild Homology of Proper Lie Groupoids

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


Jean-Michel Bismut

type: Person

cs: Matematika

de: Mathematik

fi: matematiikka

uk: Математика

en: Mathematics

fr: Mathématiques

da: Matematik

es: Matemáticas

nl: Wiskunde

de: Mathematik, Naturwissenschaften

uk: Математика, природничі науки

en: Mathematics, Natural Sciences

description: The hypoelliptic Laplacian gives a natural interpolation between the Laplacian and the geodesic flow. This interpolation preserves important spectral quantities. I will explain its construction in the context of compact Lie groups: in this case, the hypoelliptic Laplacian is the analytic counterpart to localization in equivariant cohomology on the coadjoint orbits of loop groups. The construction for noncompact reductive groups ultimately produces a geometric formula for the semisimple orbital integrals, which are the key ingredient in Selberg trace formula. In both cases, the construction of the hypoelliptic Laplacian involves the Dirac operator of Kostant.

TIB AV-Portal

type: Service

type: WebContent

type: MediaObject

@language: en

cs: přihlášení není vyžadováno

de: keine Anmeldung erforderlich

uk: вхід без авторизації

en: no login required

nl: geen login vereist

name: Hypoelliptic Laplacian and the trace formula

type: Organization

cs: Video

de: Video

fi: Video

uk: Відео

en: Video

fr: Vidéo

da: Video

nl: Video

es: Video


Generalized products and Quantization

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

description: Given a finite dimensional irreducible complex representation of G=SOo(d,1), one can associate a canonical flat vector bundle E together with a canonical bundle metric h to any finite volume hyperbolic manifold X of dimension d. For d odd and provided X satisfies some mild hypotheses, we will explain how, by looking at a family of compact manifolds degenerating to X in a suitable sense, one can obtain a formula relating the analytic torsion of (X,E,h) with the Reidemeister torsion of an associated manifold with boundary. As an application, we will indicate how, in the arithmetic setting, this formula can be used to derive exponential growth of torsion in cohomology for various sequences of congruence subgroups. This is a joint work with Werner Mueller.

uk: вхід без авторизації

name: Torsion on hyperbolic manifolds of finite volume


Diff-equivariant index theory

uk: Математика, природничі науки

description: In the early eighties, Connes developed his Noncommutative Geometry program, mostly to extend index theory to situations where usual tools of differential topology are not available. A typical situation is foliations whose holonomy does not necessarily preserve any transverse measure, or equivalently the orbit space of the action of the full group of diffeomorphisms of a manifold. In the end of the nineties, Connes and Moscovici worked out an equivariant index problem in these contexts, and left a conjecture about the calculation of this index in terms of characteristic classes. The aim of this talk will be to survey the history of this problem, and explain partly our recent solution to Connes-Moscovici's conjecture, focusing on the part concerning `quantization'. No prior knowledge of Noncommutative Geometry will be assumed, and part of this is joint work with Denis Perrot.

uk: вхід без авторизації


uk: Математика, природничі науки

description: We study the Berezin-Toeplitz quantization using as quantum space the space of eigenstates of the renormalized Bochner Laplacian on a symplectic manifold, corresponding to eigenvalues localized near the origin. We show that this quantization has the correct semiclassical behavior and construct the corresponding star-product. This is joint work with L. Ioos, W. Lu and X. Ma.

uk: вхід без авторизації

name: Berezin-Toeplitz quantization for eigenstates of the Bochner-Laplacian on symplectic manifolds


uk: Математика, природничі науки

uk: вхід без авторизації

name: Index theory and secondary spectral invariants to understand moduli spaces of Riemannian metrics (a survey)


uk: Математика, природничі науки

uk: вхід без авторизації

name: Equivariant index theory in the noncompact context, and the relation to quantisation, reduction and PSC metrics (a survey)


Multilinear maps and obfuscation

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Private k-Means with Constant Multiplicative Error


Model-Agnostic Private Learning

uk: Математика, природничі науки

uk: вхід без авторизації


Concentrated Differential Privacy

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: On Algorithmic Fairness Between Groups and Individuals


uk: Математика, природничі науки

uk: вхід без авторизації

name: A Hybrid of Advocacy and Modeling for Differential Privacy


uk: Математика, природничі науки

uk: вхід без авторизації

name: Differential Privacy for Functional Data Analysis


uk: Математика, природничі науки

uk: вхід без авторизації

name: PSI: A (differentially) private data-sharing interface


Generative Adversarial Privacy

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Local Differential Privacy for Evolving Data


uk: Математика, природничі науки

uk: вхід без авторизації

name: Individual Sensitivity Preprocessing for Data Privacy


End-to-End Analysis of PATE

uk: Математика, природничі науки

uk: вхід без авторизації


Privacy-preserving prediction

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Revisiting Differentially Private Matrix Completion


Privacy Amplification by Iteration

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Bayesian models for adaptive data analysis


Geometric Algorithms for Query Release

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Privately learning high-dimensional distributions


uk: Математика, природничі науки

uk: вхід без авторизації

name: Differentially Private Hypothesis Testing and Property Estimation


uk: Математика, природничі науки

uk: вхід без авторизації

name: Accuracy First: Selecting a DP Level for Accurate ERM

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

uk: вхід без авторизації

name: Privacy-Preserving GANs Support Clinical Data Sharing


uk: Математика, природничі науки

uk: вхід без авторизації

name: Preventing Fairness Gerrymandering: Auditing and Learning for Subgroup Fairness


cs: Informatika

de: Informatik

fi: tietojenkäsittelytiede

uk: Комп'ютерні науки

en: Computer Science

fr: Informatique

da: Datalogi

es: Ciencias de la Computación

nl: Informatica

uk: Бібліотекознавство, документознавство

en: Information and Library Sciences

de: Geisteswissenschaften

uk: Гуманітарні науки

en: Humanities

cs: Technické vědy

de: Ingenieurwissenschaften

fi: tekniikka

uk: Інженерія

en: Engineering Sciences

fr: Ingénierie

da: Ingeniørvidenskab

es: Ingeniería

nl: Engineering

uk: вхід без авторизації

name: FAIR Research Information in Open Infrastructures

Leibniz Universität Hannover (LUH)

addressCountry: DE

addressLocality: Hanover

addressRegion: Lower Saxony


uk: Математика, природничі науки

uk: вхід без авторизації

name: Immune Search and Immune Information-Transfer


uk: Математика, природничі науки

uk: вхід без авторизації

name: What contributes to scale invariance in adaptive immune response?: And are adaptive immune responses, in fact, scale invariant?


The CD8 T cell ecosystem

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Wandering cells: dissecting spatio-temporal regulation of humoral immune response.


uk: Математика, природничі науки

uk: вхід без авторизації

name: Why do Fibroblastic Reticular Cell networks in lymph nodes have small world properties?


uk: Математика, природничі науки

uk: вхід без авторизації

name: Organized spatial structure of tissue-resident T-cells in mice and humans


uk: Математика, природничі науки

uk: вхід без авторизації

name: Random distributions and random migration in homeostasis and immune responses


uk: Математика, природничі науки

uk: вхід без авторизації

name: Environmental influences on T cell motion in intact tissues


uk: Математика, природничі науки

uk: вхід без авторизації

name: Near-physiological Microfluidic Models of Leukocyte Behavior: Challenges and Some Solutions


uk: Математика, природничі науки

uk: вхід без авторизації

name: Actin flows in cell migration: from locomotion to trajectories


uk: Математика, природничі науки

uk: вхід без авторизації

name: Analyzing Protein-Protein Interactions Governing Focal Adhesion Dynamics and Stability


uk: Математика, природничі науки

uk: вхід без авторизації

name: Imaging pathogen, endothelial cell and T cell interactions in the vascular compartment


uk: Математика, природничі науки

uk: вхід без авторизації

name: Real-time data processing for imaging of immune cell motility


uk: Математика, природничі науки

uk: вхід без авторизації

name: The Fast And The Curious: How can T cells evolve migration patterns to optimize their search for antigen?


O-minimal flows on nilmanifolds

uk: Математика, природничі науки

description: Let G be a real algebraic unipotent group and let Lambda be a lattice in G, with p:G->G/Lambda the quotient map. Given a definable subset X of G, in some o-minimal expansion of the reals, we describe the closure of p(X) in G/Lambda in terms definable families of cosets of real algebraic subgroups of G of positive dimension. The family is extracted from X independently of Lambda.

uk: вхід без авторизації

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: Adler, Casanovas and Pillay proved that if p is a complete stable type over a set B which does not fork over a set A, then the restriction of p to A is also stable. I will address the analogous question, replacing stable with NIP. In addition I will present a new proof for the stable case which uses elementary techniques.

uk: вхід без авторизації

name: Non-forking and preservation of NIP types


uk: Математика, природничі науки

description: In recent work with Krupiński, we showed that strong type spaces can be seen (in a strong sense) as quotients of compact Polish groups, and as a consequence. I will give a brief account of the argument, as well as describe some applications, such as showing that a non-definable analytic subgroup of a type-definable group has index continuum (and in particular, that an analytic subgroup cannot have countably infinite index).

uk: вхід без авторизації

name: Strong type spaces as quotients of Polish groups


Metastability

uk: Математика, природничі науки

description: In their work on the model theory of algebraically closed valued fields, Haskell, Hrushovski and Macpherson developed a notion of stable domination and metastability which tries to capture the idea that in an algebraically closed valued field, numerous behaviors are (generically) controlled by the value group and/or the residue field. In this talk I will explain how (finite rank) metastability can be used to decompose commutative definable groups, in term of stable groups and value group internal groups. Time permitting, I will quickly describe the applications of these results to the study of algebraically closed valued fields, in particular, the classification of interpretable fields.

uk: вхід без авторизації


Monotone theories

uk: Математика, природничі науки

uk: вхід без авторизації


Linear orders in NIP theories

uk: Математика, природничі науки

description: A longstanding open questions asks whether an unstable NIP theory interprets an infinite linear order. I will present a construction giving a type-definable linear (quasi-)order, thus partially answering this question.

uk: вхід без авторизації


Amenability and definability

uk: Математика, природничі науки

uk: вхід без авторизації


Localized Lascar group

uk: Математика, природничі науки

description: The notion of the localized Lascar-Galois group GalL(p) of a type p appeared recently in the context of model-theoretic homology groups, and was also used by Krupinski, Newelski, and Simon in the context of topological dynamics. After a brief introduction of the context, we will discuss some basic properties of localized Lascar-Galois groups. Then, we will focus on the question about how far GalL(tp(acl(a))) can be from GalL(tp(a)). This is a joint work with B. Kim, A. Kolesnikov and J. Lee.

uk: вхід без авторизації


Interpolative Fusions

uk: Математика, природничі науки

uk: вхід без авторизації


NSOP_1 theories

uk: Математика, природничі науки

description: Let T be an NSOP1 theory. Recently I. Kaplan and N. Ramsey proved that in T, the so-called Kim-independence (ϕ(x,a0) Kim-divides over A if there is a Morley sequence ai such that {ϕ(x,ai)}i is inconsistent) satisfies nice properties over models such as extension, symmetry, and type-amalgamation. In a joint work with J. Dobrowolski and N. Ramey we continue to show that in T with nonforking existence, Kim-independence also satisfies the properties over any sets, in particular, Kim’s lemma, and 3-amalgamation for Lascar types hold. Modeling theorem for trees in a joint paper with H. Kim and L. Scow plays a key role in showing Kim’s lemma. If time permits I will talk about a result extending the non-finiteness (except 1) of the number of countable models of supersimple theories to the NSOP1 theory context.

uk: вхід без авторизації


uk: Математика, природничі науки

description: There are multiple connections between model-theoretic notions of complexity and machine learning. NIP formulas correspond to PAC-learning by way of VC-dimension, and stable formulas correspond to online learning by way of Littlestone dimension, also known as Shelah's 2-rank. We explore a similar connection between formulas without the finite cover property and equivalence query learning. In equivalence query learning, a learner attempts to identify a certain set from a set system by making hypotheses and receiving counterexamples. We use the notion of (strong) consistency dimension, an analogue of the the negation of the finite cover property for set systems. We show that finite (strong) consistency dimension and finite LIttlestone dimension characterize equivalence query learning, drawing on ideas from model theory. We also discuss the role of Littlestone dimension and strong consistency dimension in algorithms.

uk: вхід без авторизації

name: Equivalence query learning and the negation of the finite cover property


uk: Математика, природничі науки

description: We give (equivalent) friendlier definitions of classifiable theories strengthen known results about how an independent triple of models can be completed to a model. As well, we characterize when the isomorphism type of a weight one extension N/M is uniquely determined by the non-orthogonality class of the relevant regular type and discuss when N is prime over Ma for some finite a∈N. This is part of an ongoing project with Elisabeth Bouscaren, Bradd Hart, and Udi Hrushovski.

uk: вхід без авторизації

name: Retro-stability: The fine structure of classifiable theories


uk: Математика, природничі науки

description: It is by now almost folklore that if T is a countably categorical theory, and M its unique countable model, then the topological group G(T) = Aut(M) is a complete invariant for the bi-interpretability class of T . This gained renewed interest recently, given the correspondences between dynamical properties of G(T) and classification-theoretic properties of T . From a model-theoretic point of view, the obvious drawback is the restriction to countably categorical theories. As a first step, I will discuss how to generalise the original result to arbitrary theories in a countable language.

uk: вхід без авторизації

name: An "Ahlbrandt-Ziegler Reconstruction" for theories which are not necessarily countably categorical


uk: Математика, природничі науки

description: In this talk we focus on groups with f-generic types definable in NTP2 theories. In particular we study the case of bounded PRC fields. PRC fields were introduced by Prestel and Basarav as a generalization of real closed fields and pseudo algebraically closed fields, where we admit having several orders. We know that the complete theory of a bounded PRC field is NTP2 and we have a good description of forking. We use some alternative versions of Hrushovski’s “Stabilizer Theorem” to describe the definable groups with f generics in PRC fields. The main theorem is that such a group is isogeneous with a finite index subgroup of a quantifier-free definable groups. In fact, the latter group admits a definable covering by multi-cells on which the group operation is algebraic. This generalizes similar results proved by Hrushovski and Pillay for (not necessarily f-generic) groups definable in both pseudo finite fields and real closed fields.

uk: вхід без авторизації

name: NTP_2 groups with f-generics and PRC fields


uk: Математика, природничі науки

uk: вхід без авторизації

name: On generalizations of the Elekes-Szabo theorem


uk: Математика, природничі науки

description: A field K is called pseudo-algebraically closed (PAC) if every absolutely irreducible variety defined over K has a K-rational point. These fields were introduced by Ax in his characterization of pseudo-finite fields and have since become an important object of model-theoretic study. A remarkable theorem of Chatzidakis proves that, in a precise sense, independent amalgamation in a PAC field is controlled by independent amalgamation in the absolute Galois group. We will describe how this theorem and a graph-coding construction of Cherlin, van den Dries, and Macintyre may be combined to construct PAC fields with prescribed model-theoretic properties.

uk: вхід без авторизації

name: Classification Theory and the Construction of PAC Fields


uk: Математика, природничі науки

description: We prove that if D=(G,+,\dots) is a strongly minimal non-locally modular group interpretable in an o-minimal expansion of a field and dim(G)=2 then D interprets an algebraically closed field K and D (as a structure) an algebraic group over K with all the induced K-structure. I will discuss some key aspects of the proof that may be of interest on their own right. Joint work with Y. Peterzile and P. Eleftheriou.

uk: вхід без авторизації

name: Strongly minimal groups interpretable in o-minimal expansions of fields


uk: Математика, природничі науки

description: I will report on joint work with Pillay and Terry on arithmetic regularity (a group theoretic analogue of Szemeredi regularity for graphs) for sets of bounded VC-dimension in finite groups, which is proved using a local version generic compact domination for NIP formulas in pseudofinite groups. I will then present more recent work on nonabelian versions of certain "inverse theorems" from additive combinatorics, which are proved using pseudofinite model theory, and can be used to give alternate proofs of NIP arithmetic regularity for certain classes of finite groups.

uk: вхід без авторизації

name: Pseudofinite groups, arithmetic regularity, and additive combinatorics


Groupoids and Relative Internality

uk: Математика, природничі науки

description: We prove that in a stable theory, some 2-analysable types give rise to type definable groupoids, with some simplicial data attached to them, extending a well-know result linking groups to internal types. We then investigate how properties of these groupoids relate to properties of types. In particular, we expose some internality criteria.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In this talk we introduce a weaker form of bi-interpretability and see how it can be used to transfer the Ramsey property across classes in different first-order languages. This is a special case of a more general theorem about what we will call color-homogenizing embeddings.

uk: вхід без авторизації

name: Transfer of the Ramsey property by semi-retractions


uk: Математика, природничі науки

description: With Gianluca Paolini (in preparation), we constructed families of strongly minimal Steiner (systemsforeveryk 3.Aquasigroupisastructurewithabinaryoperationsuchthatforeachequationxy=zthevaluesoftwoofthevariablesdeterminesauniquevalueforthethird.Hereweshowthatthe2^{ Steiner (2,3)-systems are definably coordinatized by strongly minimal Steiner quasigroups and the Steiner (2,4)-systems are definably coordinatized by strongly minimal SQS-Skeins. Further the Steiner (2,4)-systems admit Stein quasigroups but depending on the choice of theory may or may not admit a definable binary function and be definably coordinatized by an Steinquasigroup.WeexhibitstronglyminimaluniformSteinertriplesystems(withrespecttotheassociatedgraphsG(a,b)(CameronandWebb)withvaryingnumbersoffinitecycles.Weshowhowtovarythetheorytoobtain2or3$-transitivity. This work inaugurates a program of differentiating the many strongly minimal sets, whose geometries of algebraically closed sets may be (locally) isomorphic to the original Hrushovski example, but with varying properties in the object language. In particular, can one organize these geometries by studying the associated algebra. This work differs from traditional work in the infinite combinatorics of Steiner systems by considering the relationship among different models of the same first order theory.

uk: вхід без авторизації

name: Strongly minimal Steiner systems Paleolithic Stability theory


Algebraicity of p-adic groups

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Small set expansion in the Johnson graph


uk: Математика, природничі науки

description: The 2-to-1 games conjecture is the weaker sibling of the famous and important Unique-games conjecture of [Khot02]. A recent sequence of four papers resolved a version of that former conjecture, which might count as a step towards a proof of the Unique-games conjecture, and in any case invalidates some approaches for refuting it. The proof relies crucially on some Expansion properties of the Grassmann-graph, an object that to our knowledge was not studied before in the context of theoretical Computer Science. In this talk I will explain the 2-to-1 and the Unique-games conjectures and their implications, the Grassman graph and its relevance, and hopefully also some key ideas of the proofs.

uk: вхід без авторизації

name: From the Grassmann graph to 2-to-2 games


Discrete harmonic analysis

uk: Математика, природничі науки

description: Boolean Function Analysis, the study of functions on the Boolean cube {0,1}^n, forms an essential part of the "theoretician's toolkit". Recently, functions on other domains (such as the Grassmann scheme) have been studied along similar lines, motivated by applications to TCS and combinatorics. I will discuss this nascent field, Discrete Harmonic Analysis, and some of the domains it has been studied on.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Nisan and Szegedy showed that low degree Boolean functions are juntas, namely, they depend only on a constant number of their variables. Kindler and Safra showed a robust version of the above: low degree functions which are almost Boolean are close to juntas. We study the same question on the p-biased hypercube, for very small p. The p-biased hypercube is a product probability space in which each coordinate is 1 with probability p and 0 otherwise. In this space most of the measure is on n-bit strings whose Hamming weight about pn << n. It turns out that here new phenomena emerge. For example, the function x_1 + ... + x_n=p (where x_i \in {0,1}) is close to Boolean but not close to a junta. We characterize low degree functions that are almost Boolean and show that they are close to a new class of functions which we call sparse juntas. An interesting aspect of our proof is a new proof paradigm that relies on a local to global agreement theorem. We cover the p-biased hypercube by many smaller dimensional copies of the uniform hypercube, and approximate our function locally via the standard Kindler-Safra theorem for constant p. We then stitch the local approximations together into one global function that is a sparse junta. The stitching is made feasible via a new local-to-global agreement theorem, which is an extension of the classical direct product results to larger dimensions. Time permitting, I'll show another application of this paradigm: extending the classical AKKLR low-degree tests to the p-biased hypercube.

uk: вхід без авторизації

name: Sparse Kindler-Safra Theorem via agreement theorems


uk: Математика, природничі науки

description: The Graph Matching problem is a robust version of the Graph Isomorphism problem: given two not-necessarily-isomorphic graphs, the goal is to find a permutation of the vertices which maximizes the number of common edges. We study a popular average-case variant; we deviate from the common heuristic strategy and give the first quasi-polynomial time algorithm, where previously only sub-exponential time algorithms were known. Based on joint work with Boaz Barak, Chi-Ning Chou, Zhixian Lei, and Yueqi Sheng.

uk: вхід без авторизації

name: (Nearly) Efficient Algorithms for the Graph Matching Problem on Correlated Random Graphs


(In)Approximability of Matrix Norms

uk: Математика, природничі науки

description: I will talk aboutthe problem of computing the operator norm of a matrix mapping vectors in the space l_p to l_q, for different values of p and q. This problem generalizes the spectral norm of a matrix (p=q=2) and the Grothendieck problem (p=\infty, q=1), and has been widely studied in various reigmes. When p greater than or equal to q, the problem exhibits a dichotomy: constant factor approximation algorithms are known if 2 lies between p and q, and is hard to approximate within almost polynomial factors otherwise. The regime when q is greater than p, known as the _hypercontractive case_, is particularly significant for various applications but much less well understood. The case with p = 2 and q > 2 was studied by [Barak et al., STOC'12] who gave sub-exponential algorithms for a promise version of the problem (which captures small-set expansion) and also proved hardness of approximation results based on the Exponential Time Hypothesis. However, no NP-hardness of approximation was known for these problems for any p < q. We study the hardness of approximating matrix norms in both the above cases. We prove the following results: - We show that for any p < q, the operator norm of a given matrix is hard to approximate within almost polynomial factors, when 2 does not lie between p and q. This suggests that similar to the non-hypercontrative setting, the case when 2 does not lie between p and q may be qualitatively different. - We also obtain new (constant factor) hardness results in the non-hypercontractive case when q <= 2 <= p. The bounds we obtain are known to be tight in the cases when either p or q equals 2.

uk: вхід без авторизації

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

uk: вхід без авторизації

name: Tutorial - Counting algorithms over matroids


The Hardest Halfspace

uk: Математика, природничі науки

uk: вхід без авторизації


Approximate Degree: A Survey

uk: Математика, природничі науки

description: The epsilon-approximate degree of a Boolean function is the minimum degree of a real polynomial that pointwise approximates f to error epsilon. Approximate degree has wide-ranging applications in theoretical computer science, from computational learning theory to communication complexity, circuit complexity, oracle separations, and even cryptography. This talk will survey what is known about approximate degree and its many applications, including striking recent progress on proving approximate degree lower bounds. This survey will also function as a primer for Mark Bun's followup talk.

uk: вхід без авторизації


uk: Математика, природничі науки

description: The epsilon-approximate degree of a Boolean function f is the least degree of a real polynomial that approximates f pointwise to within error epsilon. Approximate degree has a number of applications throughout theoretical computer science. As one example, a lower bound on the approximate degree of a function automatically implies a lower bound on its quantum query complexity. I will describe recent progress proving approximate degree lower bounds using the "method of dual polynomials," a framework based on linear programming duality. Our new techniques for constructing dual polynomials yield a nearly tight lower bound on the approximate degree of AC^0, and settle (or nearly settle) the quantum query complexities of several specific functions of interest in quantum computing.

uk: вхід без авторизації

name: Approximate degree and quantum query lower bounds via dual polynomials


Tutorial - Quantum PCP

uk: Математика, природничі науки

description: Two equivalent formulations of the classical PCP theorem, hardness of approximation for constraint satisfaction problem and hardness of approximation for the value of two-player games, lead to two distinct formulations of a quantum PCP conjecture. The first conjecture, the "Hamiltonian QPCP", comes out of condensed-matter physics. The second conjecture, the "games QPCP", is closely tied to questions from foundations of quantum mechanics and has applications to quantum cryptography. In the first part of the tutorial I will motivate and formulate the two conjectures. I will not assume background in quantum information, and keep the technical aspects light while still aiming to say enough to provide concrete intuition. In the second part of the tutorial I will dive deeper into the "games PCP" conjecture, on which there has been more progress recently. I will describe the issues that arise when considering classical techniques such as the Hadamard code or low-degree tests in the quantum settings. Time allowing, these investigations will bring us to a new, group-theoretic perspective on the classical tests.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Recovering a hidden signal or structure in the presence of random noise is a recurring theme in fundamental problems arising in computational complexity, cryptography, machine learning, and statistics. In the recent years, a Sum-of-Squares method, a hierarchy of generic semi-definite programming relaxations, has yielded a systematic approach for such "parameter estimation" problems. In this talk, I'll illustrate the SoS method for parameter estimation by means of a recent application of to learning mixture of gaussians with information theoretically optimal cluster-separation in quasi-polynomial time. No sub-exponential time algorithm was previously known in this regime.

uk: вхід без авторизації

name: (Quasi)-Efficiently Learning Mixtures of Gaussians at the Statistically Optimal Separation


uk: Математика, природничі науки

description: I will present an algorithm that achieves the claim in the title.

uk: вхід без авторизації

name: Approximation edit distance within a constant factor in truly subquadratic time


Fooling polytopes

uk: Математика, природничі науки

description: We give an explicit pseudorandom generator with seed length poly(log m, 1/\delta) * log n that \delta-fools the class of all m-facet polytopes over {0,1}^n. The previous best seed length had linear dependence on m. As a corollary, we obtain a deterministic quasipolynomial time algorithm for approximately counting the number of feasible solutions of general {0,1}-integer programs.

uk: вхід без авторизації


Oracle Separation of BQP and the PH

uk: Математика, природничі науки

description: We present an oracle, A, relative to which BQP^A is not contained in PH^A. Following the approach of Aaronson [STOC, 2010], our oracle separation is obtained by finding a distribution D over Boolean strings of length N such that: (1) There exists a quantum algorithm that runs in time polylog(N) and distinguishes between D and the uniform distribution over Boolean strings of length N. (2) No AC0 circuit of quasi-polynomial size can distinguish between D and the uniform distribution with advantage better than polylog(N)/sqrt(N).

uk: вхід без авторизації


Proof of the GM-MDS conjecture

uk: Математика, природничі науки

description: A k x n matrix is an MDS matrix if any k columns are linearly independent. Such matrices span MDS (Maximum Distance Separable) codes. A standard construction of such matrices is by Vandermonde matrices, which generate the Reed-Solomon codes. The following question arose in several applications in coding theory: what zero patterns can MDS matrices have? it turns out that there is a simple combinatorial characterization that is both necessary and sufficient over large enough fields (concretely, of size {n \choose k}). It was conjectured by Dau et al in 2014 that the same combinatorial characterization is also sufficient over much smaller fields, of size n+k-1. This conjecture is called the GM-MDS conjecture. Dau et al proposed an algebraic conjecture on the structure of polynomials which would imply the GM-MDS conjecture. It speculates that the GM-MDS conjecture can be resolved by an "algebraic" construction. We prove this algebraic conjecture, and as a corollary also the GM-MDS conjecture.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In this talk, we consider the problem of explicitly constructing a binary tree code with constant distance and constant alphabet size. We present an explicit binary tree code with constant distance and alphabet size polylog(n), where n is the depth of the tree. This is the first improvement over a two-decade-old construction that has an exponentially larger alphabet of size poly(n). For analyzing our construction, we prove a bound on the number of integral roots a real polynomial can have in terms of its sparsity with respect to the Newton basis - a result of independent interest.

uk: вхід без авторизації

name: Explicit Binary Tree Codes with Poly-Log Size Alphabet


Proof Complexity for SAT practitioner

uk: Математика, природничі науки

description: Running a SAT solver on an UNSAT formula produces (implicitly or explicitly) a proof that the formula is unsatisfiable, usually expressible in an established formal language called proof system. This observation leads to study SAT solving methods by looking at the generated proofs. I.e., if an UNSAT formula has no short proof in a given proof system, the corresponding SAT solvers cannot solve the formula efficiently. We introduce the area and the methods of proof complexity, that studies the length and the structure of proofs of UNSAT. In particular we define and discuss Resolution, Polynomial Calculus, Cutting Planes and Extended Resolution, which are the most relevant proof systems for current SAT solver technology. Since a SAT solver goal is, among other things, to look for proofs as short as possible, we briefly discuss the complexity of efficiently finding such short proofs.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In this talk, we will present the basic principles of SAT solvers, by focusing on the essential ingredients most of the best SAT solvers embed. The practical applications of SAT solvers have attracted a lot of attention in the recent years, which is probably due to their ability to solve problems encoded in SAT more efficiently than adhoc methods. However, on these problems (where SAT solvers show very good results) the reasons for their efficiency remains largely unknown. We will thus also present a few experimental observations we gathered over the years. This should cast some lights on some of their mode of operation, sometimes counter intuitively, and stimulate further discussions.

uk: вхід без авторизації

name: Towards an (experimental) understanding of SAT Solvers


Computable Short Proofs

uk: Математика, природничі науки

description: The success of satisfiability solving presents us with an interesting peculiarity: modern solvers can frequently handle gigantic formulas while failing miserably on supposedly easy problems. Their poor performance is typically caused by the weakness of their underlying proof system—resolution. To overcome this obstacle, we need solvers that are based on stronger proof systems. Unfortunately, existing strong proof systems—such as extended resolution or Frege systems—do not seem to lend themselves to mechanization. We present a new proof system that not only generalizes strong existing proof systems but that is also well-suited for mechanization. The proof system is surprisingly strong, even without the introduction of new variables—a key feature of short proofs presented in the proof-complexity literature. We demonstrate the strength of the new proof system on the famous pigeon hole formulas by providing short proofs without new variables. Moreover, we introduce satisfaction-driven clause learning, a new decision procedure that exploits the strengths of our new proof system and can therefore yield exponential speed-ups compared to state-of-the-art solvers based on resolution.

uk: вхід без авторизації


Symmetry in SAT: an overview

uk: Математика, природничі науки

description: Many a mathematical proof presents a symmetry argument to bypass an otherwise cumbersome case distinction. Similarly, combinatorial solvers can exploit symmetry to reduce the search space. This talk gives an overview of the techniques used in SAT solving to exploit symmetry properties of the problem at hand. It covers the topics of symmetry detection - typically via a transformation to graph automorphism though an argument for other approaches can be made; types of symmetry - different types have different needs; static and dynamic symmetry breaking - which remove symmetrical solutions from the solution set; symmetrical learning - which adds a symmetry rule to CDCL's proof system; and completeness of symmetry exploitation techniques - which arguably is the ultimate goal. The talk elaborates on the strengths and weaknesses of each technique, highlighting open questions and future research opportunities. As a common thread, we discuss the performance of each technique on the SAT encoding of the pigeonhole principle, which -in theory- can be decided in polynomial time using a symmetry argument. In practice however, efficiently deciding the SAT encoding of the pigeonhole principle remains a daunting challenge, as even after decades of research, none of the current techniques is able to fully detect and exploit the available symmetry.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Over the last decades Boolean satisfiability (SAT) solvers based on conflict-driven clause learning (CDCL) have developed to the point where they can handle formulas with millions of variables. Yet a deeper understanding of how these solvers can be so successful has remained elusive. In this work we try to shed light on CDCL performance by using theoretical benchmarks. While these are crafted instances, they have the attractive features of being a) scalable, b) extremal with respect to different proof search parameters, and c) theoretically *easy* in the sense of having short proofs in the resolution proof system underlying CDCL. This allows for a systematic study of solver heuristics and how successfully they implement efficient proof search. We report results from extensive experiments with different CDCL parameter configurations on a wide range of benchmarks. Our findings include several examples where theory predicts and explains CDCL behaviour, but also raises a number of intriguing questions for further study.

uk: вхід без авторизації

name: Seeking Practical CDCL Insights from Theoretical SAT Benchmarks


uk: Математика, природничі науки

description: Finding a maximum clique in a graph is one of the most basic computational problems on graphs. The various applications of this problem has motivated the design of algorithms which today can successfully solve real-world instances with thousands of vertices.

uk: вхід без авторизації

name: Clique Is Hard for State-of-the-Art Algorithms


uk: Математика, природничі науки

description: Since 2014, several leading theoreticians and experimentalists conducting research on Boolean satisfiability (SAT) solving have been meeting annually to stimulate an increased exchange of ideas between these two communities. The hope has been for for a fruitful interplay between theoretical and experimental research in this area, with the belief that a more vigorous interaction between the two has potential for major long-term impact in computer science and mathematics, as well for applications in industry. in this fifth meeting of this group, it is appropriate to ask how successful has the interplay between theoretical and experimental research in SAT solving. In this brief talk, I will outline some areas of real progress. At the same, I will argue that progress has been rather mild relative to expectations, and suggest some concrete research directions that could be pursued to advance the theory and engineering of SAT solving.

uk: вхід без авторизації

name: Boolean Satisfiability: Theory and Engineering


uk: Математика, природничі науки

description: The last 20 years have seen dramatic improvements in the performance of algorithms for Boolean satisfiability---so-called SAT solvers---and today conflict-driven clause learning (CDCL) solvers are routinely used in a wide range of application areas. One serious short-coming of CDCL, however, is that the underlying method of reasoning is quite weak. A tantalizing solution is to instead use stronger pseudo-Boolean (PB) reasoning (a.k.a. 0-1 integer linear programming), but so far the promise of exponential gains in performance has mostly failed to materialize---the increased theoretical strength seems hard to harness algorithmically, and in many applications CDCL-based methods are still superior. In this talk, we will discuss conflict-driven search and how to lift it from clauses to pseudo-Boolean linear constraints. We will survey the "classic" method in [Chai and Kuehlmann '05] based on saturation, and then describe a relatively new approach from [Elffers and Nordström '18] instead using division. We will also try to highlight some of the obstacles that remain along the path to truly efficient pseudo-Boolean solvers.

uk: вхід без авторизації

name: Towards Faster Conflict-Driven Pseudo-Boolean Solving


uk: Математика, природничі науки

description: Understanding properties of deep neural networks is an important challenge in deep learning. Deep learning networks are among the most successful artificial intelligence technologies that is making impact in a variety of practical applications. However, many concerns were raised about `magical' power of these networks. It is disturbing that we are really lacking of understanding of the decision making process behind this technology. Therefore, a natural question is whether we can trust decisions that neural networks make. One way to address this issue is to define properties that we want a neural network to satisfy. Verifying whether a neural network fulfills these properties sheds light on the properties of the function that it represents. In this work, we take the verification approach. Our goal is to design a framework for analysis of properties of neural networks. We start by defining a set of interesting properties to analyze. Then we focus on Binarized Neural Networks that can be represented and analyzed using well-developed means of Boolean Satisfiability and Integer Linear Programming. One of our main results is an exact representation of a binarized neural network as a Boolean formula. We also discuss how we can take advantage of the structure of neural networks in the search procedure.

uk: вхід без авторизації

name: Formal Analysis of Deep Binarized Neural Networks


Pseudo-Boolean Optimization

uk: Математика, природничі науки

description: Very often, problems modeled using pseudo-Boolean constraints are optimization problems, not satisfaction problems. Because of the very efficient SAT solvers available, many of those optimization problems can be solved by reusing those solvers as black boxes. In this talk, we will provide some insights about the reason of the success of the black box approaches, some of their limitations, and raise open problems to design more efficient Boolean optimizers.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Pseudo-Boolean solvers that generalize the CDCL algorithm and reason within the cutting planes proof system can have a theoretical advantage with respect to solvers that just translate the problem and apply the standard CDCL algorithm, which is limited to resolution. In practice, however, results are mixed. Do we need a better theory, better solvers, or both? One key observation is that implementation constraints limit solvers to a subset of inference rules. In this talk we identify subsystems of cutting planes that arise from these limited rules and we classify them, showing in particular that pseudo-Boolean solvers are limited to resolution if their input is encoded adversarially. Guided by these theoretical insights we craft formulas that lie within the limits of pseudo-Boolean solvers and test them in practice. Alas, current solvers perform terribly on these benchmarks, but we can at least extract concrete obstacles for upcoming solvers to overcome.

uk: вхід без авторизації

name: A Proof Complexity View of Pseudo-Boolean Solving


uk: Математика, природничі науки

description: There is an increasing interplay between practical implementations of Sat Solvers and theoretical results about proof complexity. In some cases, theory can be useful for understanding or designing Sat solvers, but the connections are not as strong as might be wished for. This talk will discuss these issues, and make some suggestions for further research directions both for theoreticians and for practitioners.

uk: вхід без авторизації

name: The (un)reasonable (in)effectiveness of theory for Sat solvers


Advances in QBF Solving

uk: Математика, природничі науки

description: In this talk I will review the recent progress in the solving of Quantified Boolean Formulas (QBF). The initial research on QBF solving focused on extending SAT technology. However, in the recent approaches SAT solvers are used in a black-box fashion and the search space is pruned by stronger constraints than just clauses. The study of QBF has also revealed a number of limitations of the existing technology. Recent results show that some of these limitations can be tackled by applying Machine Learning at the semantic level.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Combinatorial problems can be represented elegantly and efficiently by systems of polynomial equations. Those systems are either feasible or infeasible, depending on whether or not the underlying combinatorial property is present or not present. In this general survey talk, we will explore the infeasible polynomial systems and their associated combinatorial Nullstellensatz certificates, and we will also explore the feasible polynomial systems and their associated Grobner bases. Along the way, we will highlight some natural questions that arise and identify specific advantages/disadvantages of these methods. We will also suggest open problems and further research directions whenever possible.

uk: вхід без авторизації

name: Hilbert’s Nullstellensatz and NP-Complete Problems


uk: Математика, природничі науки

description: This talk will give an overview of the relatively young field of QBF proof complexity, explaining QBF proof systems (including QBF resolution, Frege and beyond). We will explore the simulation order of different QBF calculi and how they correspond to ideas in QBF solving. A particular focus of the talk will be on lower bound techniques for QBF systems and in particular new ideas, which do not just lift propositional hardness, but exploit hardness stemming from quantifier dependencies.

uk: вхід без авторизації

name: Proof Complexity of Quantified Boolean Formulas


Gröbner bases and applications

uk: Математика, природничі науки

description: At a Dagstuhl meeting a few years ago, I gave a tutorial lecture about Groebner bases whose emphasis was on their defining properties and the classical algorithms for computing them. In this year's tutorial, I will focus more on what we can do with Groebner bases and polynomial ideal theory. The plan is to cover some of the standard situations in which Groebner bases are helpful, as well as some recent joint work with Armin Biere and Daniela Ritirc on using Groebner bases for circuit verification.

uk: вхід без авторизації


A Survey on Exact Algorithms of SAT

uk: Математика, природничі науки

description: I will survey work on exact algorithms for SAT, analyzed by their worst-case complexity. I will mention some of the algorithmic paradigms and methods of analysis used, and propose several directions for further research.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In this talk I will both give a review of the behaviour of random k-sat formulae and present some new variations on the problem. In the study of random K-sat one constructs a k-sat formula with n variables and m clauses at random. When m is small the formula is most often satisfiable and when m i large it is most likely unsatisfiable. We also know that there is a sharp transition between these to cases, often referred to as a phase transition. Empirically is has been observed that sat-solvers have a peak in their typically running time when m is close to this phase transition, and a longer number of conjectures has been made about this behaviour. I will review what is now known from mathematical results and also discuss how well, or badly, some of the old conjectures and observations have held up against both mathematics and recent, far more extensive, experiments. I will also mention some recent work on unbalanced versions of k-sat which display interesting behaviours.

uk: вхід без авторизації

name: Random k-sat. A review and some new results.


Conflict-Driven Synthesis

uk: Математика, природничі науки

description: Program synthesis is expanding rapidly and getting a lot of attention from both industry and academia. The goal of program synthesis is to find a program that satisfies the user intent expressed in the form of some specification. Program synthesis has proven to be useful to both end-users and programmers. For instance, program synthesis has been used to automate tedious tasks that arise in everyday life, such as string manipulations in spreadsheets or data wrangling tasks in R. Program synthesis has also been used for improving programmer productivity by automatically completing parts of a program or helping programmers use complex APIs.

uk: вхід без авторизації

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: One of the oldest and weakest calculi for quantified Boolean formulas (QBF) is Q-Resolution. It consists of two rules: the resolution rule similar as in propositional logic and the universal reduction rule. In its most basic variant, resolution is allowed only over existential variables. More powerful proof systems can be obtained by allowing resolution over the universal variables as well or by introducing so-called long-distance resolution. Separations are shown by using the well-investigated formulas introduced by Kleine Buening and other (the so-called KBKF formulas). In this talk, we enrich the (relatively weak) QBF resolution calculus with the Symmetry Rule that exploits symmetries of the input formula. With this simple rule, we obtain separations to powerful QBF calculi by showing that the KBKF formulas and extensions become easy when the symmetry rule may be used.

uk: вхід без авторизації

name: The Symmetry Rule for Quantified Boolean Formulas


uk: Математика, природничі науки

description: The resolution proof system has been enormously helpful in deepening our understanding of conflict-driven clause-learning (CDCL) SAT solvers. In the interest of providing a similar proof complexity-theoretic analysis of satisfiability modulo theories (SMT) solvers, we introduce a generalization of resolution called Res(T). We show that many of the known results comparing resolution and CDCL solvers lift to the SMT setting, such as the result of Pipatsrisawat and Darwiche showing that CDCL solvers with ``perfect'' non-deterministic branching and an asserting clause-learning scheme can polynomially simulate general resolution. We also describe a stronger version of Res(T), Res*(T), capturing SMT solvers allowing introduction of new literals. We analyze the theory EUF of equality with uninterpreted functions, and show that the Res*(EUF) system is able to simulate an earlier calculus introduced by Bjorner and De Moura for the purpose of analyzing DPLL(EUF). Further, we show that Res*(EUF) (and thus SMT algorithms with clause learning over EUF, new literal introduction rules and perfect branching) can simulate the Frege proof system, which is well-known to be far more powerful than resolution. Finally, we prove under the Exponential Time Hypothesis (ETH) that any reduction from EUF to SAT (such as the Ackermann reduction) must, in the worst case, produce an instance of size at least n log n from an instance of size n.

uk: вхід без авторизації

name: Proof complexity of Satisfiability Modulo Theories


uk: Математика, природничі науки

description: It has been well-established that CDCL SAT solvers with restarts can simulate general resolution. However, these results require that the solver use a highly nondeterministic or sufficiently random decision strategy. Our goal is to understand the impact of more explicit decision strategies on the theoretical strength of CDCL. Since decisions strategies used in practice are somewhat complicated, we instead focus on the simpler ordered decision strategy: when the solver has to choose a variable to assign, it must choose the smallest unassigned variable according to some underlying order. This strategy was studied by Beame et. al. (2002) in the context of DLL without clause learning. It is still possible for unit propagation to assign variables out of order, which is what makes this situation more subtle and non-trivial. Our motivating question is the following: is there a family of unsatisfiable formulas that possess polynomial size resolution refutations but require super-polynomial time for CDCL using the ordered decision strategy? We present preliminary results towards this end. First, we show that CDCL with the ordered decision strategy and the so-called DECISION learning scheme is no more powerful than ordered resolution. Second, we show that CDCL with the ordered decision strategy and a somewhat powerful learning scheme we call FIRST-L (similar to FirstNewCut introduced by Beame et. al. (2004)) is equivalent to general resolution, given it can ignore unit clauses and conflicts. This result may be interpreted as demonstrating that mandatory unit propagation or conflict analysis is, in some sense, necessary to positively answer our the question above. To aid this work, we also present a model and language for discussing CDCL-based proof systems. This is not meant to be novel and is heavily influenced by previous works. But rather than being faithful to practical SAT-solver implementations, the goal of our model is highlighting possible non-standard sources of nondeterminism. It allows for clear and concise mathematical statements about CDCL-based proof systems and better represents the landscape of potential CDCL variants.

uk: вхід без авторизації

name: On CDCL-based Proof Systems with the Ordered Decision Strategy


uk: Математика, природничі науки

description: Conflict-driven clause learning (CDCL) is at the core of the success of modern SAT solvers. In terms of propositional proof complexity, CDCL has been shown as strong as general resolution. Improvements to SAT solvers can be realized either by improving existing algorithms, or by exploiting proof systems stronger than CDCL. Recent work proposed an approach for solving SAT by reduction to dual-rail MaxSAT. The proposed reduction coupled with MaxSAT resolution represents a new proof system, DRMaxSAT, which was shown to enable polynomial time refutations of pigeonhole formulas, in contrast with either CDCL or general resolution.

uk: вхід без авторизації

name: Algorithms for Satisfiability beyond Resolution


uk: Математика, природничі науки

uk: вхід без авторизації

name: A few results, questions, and pitfalls in the experimental study of SAT solvers


Machine Learning for SAT Solvers

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

description: Many applications in hardware and software verification rely on Satisfiability Modulo Theories (SMT) solvers for bit-precise reasoning. For solving quantifier-free bit-vector formulas, current state-of-the-art is a technique called bit-blasting, which eagerly translates a given formula into propositional logic (SAT). Bit-blasting is efficient in practice, but may not scale if the input size can not be reduced sufficiently during preprocessing. For quantified bit-vector logics, the majority of solvers employ instantiation-based techniques, which aim to find conflicting ground instances of quantified formulas. For that, it is crucial to select good instantiations for the universal variables, or else the solver may be overwhelmed by the number of ground instances generated. In this talk I will present a complete propagation-based local search approach for quantifier-free bit-vector formulas. It utilizes conditional inverse value computation on concrete assignments for down-propagation. Computing inverse values of bit-vector operators is not always possible, but we can derive conditions that precisely characterize when bit-vector constraints are invertible. We utilized syntax-guided synthesis techniques to aid in establishing these conditions and verified them independently by using several SMT solvers. I will show how such invertibility conditions can be embedded into quantifier instantiations using Hilbert choice expressions.

uk: вхід без авторизації

name: From Local Search to Quantifier Elimination for Bit-Vectors in SMT


Circular (Yet Sound) Proofs

uk: Математика, природничі науки

description: We introduce a new way of composing proofs in rule-based proof systems that generalizes tree-like and dag-like proofs. In the new definition, proofs are directed graphs of derived formulas, in which cycles are allowed as long as every formula is derived at least as many times as it is required as a premise. We call such proofs circular. We show that, for all sets of standard inference rules, circular proofs are sound. For Frege we show that circular proofs can be converted into tree-like ones with at most polynomial overhead. For Resolution the translation can no longer be a Resolution proof because, as we show, the pigeonhole principle has circular Resolution proofs of polynomial size. Surprisingly, as proof systems for deriving clauses from clauses, Circular Resolution turns out to be equivalent to Sherali-Adams, a proof system for reasoning through polynomial inequalities that has linear programming at its base. As corollaries we get: 1) polynomial-time (LP-based) algorithms that find circular Resolution proofs of constant width, 2) examples that separate circular from dag-like Resolution, such as the pigeonhole principle and its variants, and 3) exponentially hard cases for circular Resolution. This is joint work with Massimo Lauria.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Itsykson and Sokolov in 2014 introduced the class of DPLL(xor) algorithms that solve Boolean satisfiability problem using the splitting by linear combinations of variables modulo 2. This class extends the class of DPLL algorithms that split by variables. DPLL(xor) algorithms solve in polynomial time systems of linear equations modulo 2 that are hard for DPLL, PPSZ and CDCL algorithms. Itsykson and Sokolov have proved first exponential lower bounds for DPLL(xor) algorithms on unsatisfiable formulas. In the talk, we discuss several subclasses of DPLL(xor) algorithms and explain lower bounds for one of them.

uk: вхід без авторизації

name: Hard Satisfiable Formulas for Splittings by Linear Combinations


keywords: Physikgeschichte Wissenschaftsgeschichte Festkörperphysik Vorlesung Nationalsozialismus

de: Physik, Astronomie

fi: fysiikka, tähtitiede

uk: Фізика, Астрономія

en: Physics, Astronomy

fr: Physique, Astronomie

da: Fysik, Astronomi

es: Física, Astronomía

nl: Natuurkunde, Astronomie

uk: Математика, природничі науки

description: Der Film behandelt das Leben des Göttinger Physikers Robert Wichard Pohl (1884-1976). Pohl war ein Pionier der Festkörperphysik und Urheber eines einflussreichen Lehrkonzeptes für die Vermittlung von Physik an Schule und Hochschule.

@language: de

uk: вхід без авторизації

name: Einfachheit ist ein Zeichen des Wahren: Leben und Werk des Physikers Robert Wichard Pohl

name: I. Physikalisches Institut der Universität Göttingen

addressLocality: Göttingen


keywords:
Open science
Open Data
Computer science

uk: Комп'ютерні науки

description: In this talk were addressed some of the main modern challenges of geospatial data science grouped around five main aspects: (i) training data issues — these include mismatches in standards when recording measurements, legal and technical issues that limit data use, high costs of producing new observational data; (ii) modeling issues — these include point clustering and extrapolation problems, model overfitting, artifacts in input data, lack of historical data, lack of consistent global monitoring stations (Kulmala, 2018), limited availability and/or quality of global covariate layers; (iii) data distribution issues — these include unusable file formats, high data volumes, incomplete or inaccurate metadata; (iv) usability issues — these include incompleteness of data, unawareness of user communities and/or data limitations, data being irrelevant for decision making; and (v) governance issues — these include closed data policies from (non-)governmental organizations, datasets not used by organizations, lack of baseline estimates, absence of strategies for updates of data products. OpenGeoHub, together with 21 partners have launched an ambitious new European Commission-funded Horizon Europe project called “Open-Earth-Monitor” which aims at tackling some of the bottlenecks in the uptake and effective usage of environmental data, both ground observations and measurements and EO data. They plan to build upon existing Open Source and Open Data projects and build a number of tools, good practice guidelines and datasets that can help cope with some of the modern challenges.

uk: вхід без авторизації

name: Modern challenges of geospatial data science: the Open-Earth-Monitor project


keywords:
Open science
Open Data
Computer science
R spatial
Tesselations
Geometry

uk: Комп'ютерні науки

description: Edzer Pebesma went through chapters 1-3 of https://r-spatial.org/book/ , and illustrated things with package sf (see ch 7). This introduces one to spatial data, vector data, tesselations, geometries, simple features, geometric predicates, geometric transformations.

uk: вхід без авторизації

name: R-spatial updates: sf, sftime, stars (R tutorial) - Part 1


keywords:
Open science
Open Data
Computer science
R
Open Reproducible Research

uk: Комп'ютерні науки

description: Open Reproducible Research (ORR) is a crucial topic in Open Science and combines several open practices, such as Open Data, Open Code, and Open Source Infrastructure. It can help us understand and tackle wicked global challenges, such as climate change, natural hazards, urbanisation, digitisation, and pandemics. But what does ORR actually mean? Is it common practice? (A little spoiler: It’s not!). What do you need to consider and are there any tools that can help you? You will find answers to these questions in this lecture and learn what is needed to achieve ORR, which obstacles make it difficult, and how ORR can contribute to increasing the transparency, verifiability, and reusability of research results.

uk: вхід без авторизації

name: Open Reproducible Research – Concepts, challenges, and solutions (R tutorial)


keywords:
Open science
Open Data
Computer science
R
Geocomputation
Geospatial analysis

uk: Комп'ютерні науки

description: Stan Openshaw defined in 2000 that "GeoComputation is about using the various different types of geodata and about developing relevant geo-tools within the overall context of a ‘scientific’ approach". In subsequent years, the idea of geocomputation gained much traction, with many new spatial data models, spatial data sources, geocomputation methods, and spatial visualizations. At the time of making the above definition, it was unrealistic to expect people to reproduce or replicate code examples automatically. Gladly, in addition to the geocomputation developments, we have seen a growing interest in reproducibility in many fields, including geocomputation. Reproducibility has many advantages, as it promotes the use of best practices, improves transparency and reusability, and allows for sharing the code and code workflows. The goal of this tutorial is to: a) provide an introduction to basic concepts of geocomputation, geocomputation with R, and reproducibility, and b) show various approaches and tools that allow for reproducibility and replicability, including R scripts, RStudio projects, {reprex}, {renv}, Git, Docker, and more. The tutorial is a mixture of theoretical and practical: each concept is first described and explained, and next, the attendees had a chance to solve problems related to geocomputation with R and reproducibility of geospatial analysis.

uk: вхід без авторизації

name: Geocomputation with R’s guide to reproducible spatial data analysis (R tutorial)


JuliaGeo: a gentle introduction

keywords:
Open science
Open Data
Computer science
JuliaGeo

uk: Комп'ютерні науки

description: Julia is a programming language that is simple to write and scriptable like Python and R, but fast like C or C++. At 10 years, it’s a young language, so the ecosystem isn’t as large and mature as you want it to be. Maarten Pronk was an early adopter of the language in his research at Deltares, a Dutch research institute. In this lecture(s) he introduced Julia, his motivation to use it and his OSS journey. Half of the lecture was non-spatial, while the latter half focused on the JuliaGeo ecosystem and showcased some of the possibilities of the Julia language.

uk: вхід без авторизації


keywords:
Open science
Open Data
Computer science
R
Vector data cube
Spatiotemporal analysis
sftime

uk: Комп'ютерні науки

description: In this second part Edzer Pebesma went through chapters 4-6 of https://r-spatial.org/book and discussed spherical geometry, spatiotemporal information, irregular spatiotemporal data in sftime, spatiotemporal raster and vector data cubes in package stars, and chapter 5 on support of spatial data.

uk: вхід без авторизації

name: R-spatial updates: sf, sftime, stars (R tutorial) - Part 2


uk: Комп'ютерні науки

description: In this workshop were compared the most popular packages for raster and vector data processing in R and Python. The differences between them were also checked, and a test was made to know which has the best performance.

uk: вхід без авторизації

name: Benchmarking R and Python for spatial data processing


uk: Комп'ютерні науки

description: In this training session you will learn about the main concepts / aspects related to raster data cubes, cloud-optimized geotiff (COG) and SpatioTemporal Asset Catalog (STAC), working with a practical example in Python. Using the eumap library and the training samples provided in the hackathon, you will perform a complete workflow for spatial predictive mapping, including:  Spacetime overlay (through STAC + COG),  Train a Random Forest classifier (with hyper-parameter optimization),  produce a classification output (also through STAC + COG). All the steps were executed in Google Colab and all the data (points and rasters) accessed directly from the cloud (http://stac.ecodatacube.eu).

uk: вхід без авторизації

name: Accessing and using data cubes: spatial overlay, visualization and modeling – Python tutorial


Introduction to mlr3 (R tutorial)

keywords:
Open science
Open Data
Computer science
mlr3

uk: Комп'ютерні науки

description: This session introduced the machine-learning framework {mlr3} in R. {mlr3} is a framework similar to {tidymodels} but based on different backends. It heavily relies on {data.table} and {future} and is built using the R6 object-oriented-programming class. Essential building blocks and basic concepts were presented to participants and applied afterwards in a hands-on tutorial part.

uk: вхід без авторизації


keywords:
Open science
Open Data
Computer science
Raster data
big dataset

uk: Комп'ютерні науки

description: In this first part, the participants saw how it is possible to visualise large cloud optimised data sets in R. They used R packages {leaflet} and {leafem}, and specifically the development version of {leafem}. They saw how to render large vector and raster data sets that are remotely hosted (an AWS S3 bucket in this case) and learned how to control styling and appearance. In this second part, they learned how to prepare their own data in order to host them in the cloud and visualise them using the tools from the first session. This part was mostly about using the command line to prepare data, rather than using R. This part was important as the future of data analysis lies more and more in the cloud and it gave the participants the means to share their large data sets with the world (or whoever they wanted to share them with).

uk: вхід без авторизації

name: Visualization cloud-optimized (large) datasets in R (R tutorial)


keywords:
Open science
Open Data
Computer science
Meteorology
Machine LEarning
Recurrent neural network
Autoencoders
Generative adversarial network

uk: Комп'ютерні науки

description: This lecture provides an introduction to deep machine learning in the domain of weather, climate and air quality research. The atmospheric is a highly complex and dynamical system in which many physical, chemical and biological processes interact on a wide range of spatial and temporal scales. As a consequence, atmospheric data has some properties that differ from other machine learning applications and established ML methods may not always work well when applied to atmospheric data. The lecture is structured into four parts. First, we discuss some general properties of the atmosphere and atmospheric data. Next, a brief summary of atmospheric statistics and evaluation metrics is given. In the third part, we will learn some machine learning fundamentals and compare machine learning models and numerical (weather) models. The fourth part provides several examples of machine learning applications in the weather and climate domain with a focus on weather forecasting. Useful readings mentioned in the presentation below. Generative adversarial network: https://towardsdatascience.com/generative-adversarial-networks-explained-34472718707a Tranformers: https://towardsdatascience.com/transformers-explained-visually-part-1-overview-of-functionality-95a6dd460452 Autoencoders guide: https://www.v7las.com/blog/autoencoders-guide

uk: вхід без авторизації

name: Machine learning for weather, air quality and climate


keywords:
Open science
Open Data
Computer science
R
CAST package
prediction models
Area of applicability

uk: Комп'ютерні науки

description: In this session the lecturer discussed current challenges of using machine learning in the context of environmental monitoring. More specifically, the suitability of different cross-validation strategies to assess the prediction performance, including novel developments like the “nearest neighbor distance matching” method, were discussed. The lecturer enabled the attendees to further learn how suitable cross-validation strategies can be used to improve prediction models by applying them during hyperparameter tuning and variable selection. Finally, she thaugh them about the “area of applicability” of spatial prediction models – to limit predictions to the area where the model was enabled to learn about relationships. In the first part of the session, she guided the attendees through the motivation and conceptual ideas of these methods. In the second session how to apply these methods in practice. The newly suggested methods are implemented in the R package CAST which we will use together with the R package caret, but the attendees also learned how to use the methods with mlr3.

uk: вхід без авторизації

name: Machine learning-based maps of the environment: challenges of extrapolation and overfitting


keywords:
Open science
Open Data
Computer science
GeoPanda
Python

uk: Комп'ютерні науки

description: The ecosystem of packages for spatial data handling and analysis in Python is extensive and covers both vector and raster analytics from small to large distributed data. This talk covers only a small part, focusing on vector data processing with GeoPandas at its core. First, it covers what GeoPandas is and how it relates to other packages and combines them into a user-friendly API. Then it looks at what GeoPandas enables with a light introduction to PySAL Python Spatial Analysis Library for spatial statistics and modelling. The final part touches on the scalability issue and introduces how to handle parallel computation and big data using GeoPandas and Dask. All of that is illustrated by hands-on tasks on real-world data.

uk: вхід без авторизації

name: Introduction to GeoPandas and its Python ecosystem


Extreme events session

keywords:
Open science
Open Data
Computer science
Extreme events
Extreme value theory
R

uk: Комп'ютерні науки

description: Even though extremes seem to occur more often in recent times, they are by definition rare events. This poses challenges on the modeling and prediction of these processes, as we have only few samples. This class is meant as a gentle introduction into extreme value theory in the uniand multivariate case. Different examples and approaches to fit models to heavy tailed distributions were shown and extensions shown to flexibly fit multivariate distributions. Models were discussed, and their implications in a spatial and spatio-temporal context. The second part of the class was devoted to a R-based hands-on session to apply the taught approaches to own data sets or demo data.

uk: вхід без авторизації


keywords:
Open science
Open Data
Computer science
Statistical test

uk: Комп'ютерні науки

description: In this contribution we will systematically walk to stochastic processes starting from random variables in 1,2, and more dimensions. We show tests and ways to create statistically relevant test data based on requirements or assumptions on the models to be tested. Emphasis is on testing strategies using standard python libraries.

uk: вхід без авторизації

name: Stochastic processes, analysis, examples (Python tutorial)


Explainable ML

keywords:
Open science
Open Data
Computer science
Machine Learning

uk: Комп'ютерні науки

description: Machine learning approaches, particularly deep neural networks, are showing tremendous success in finding patterns and relationships in large datasets for prediction and classification, which are typically too complex for humans to grasp directly. In many cases, models are learned for automation as soon as manual analysis and interpretation of the data are too costly. Explainable machine learning, which analyzes the decision-making process of machine learning methods in more detail, is used whenever an explanation of the result is needed in addition to the result. This can be for various reasons, such as increasing trust in the result or deriving new scientific knowledge that can be inferred from patterns in the decision-making process of the machine learning model. In this lecture, we will consider the basics of explainable machine learning, reasons to seek explanations, and some applications and methods from close-range and satellite-based remote sensing. Applications include whale detection, ozone value estimation, and discovery of wilderness characteristics.

uk: вхід без авторизації


Geo-arrow and geo-parquet

keywords:
Open science
Open Data
Computer science
Geo-arrow
Geo-parquet
spatial analysis
Python
R

uk: Комп'ютерні науки

description: Apache Arrow and Apache Parquet are upcoming formats (standards, with software libraries) for cloud-native data in columnar storage; their geo-varieties, geoarrow and geoparquet do the same for simple feature (vector) spatial data. In this lecture, the lecturers tried to explain what this means (“cloud-native”, “columnar storage”, “chunking”), what the correspondence and difference between arrow and parquet are, why and when you would (or would not) want to use them, and demonstrated how to use them, using R and/or Python.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Minkowski space of dimension 2+1 is the Lorentzian analogue of Euclidean 3-space. It is well-known that the Gauss map of a Riemannian surface of constant mean curvature (CMC) in Minkowski space is harmonic, while the Gauss map of a surface of constant Gaussian curvature (CGC) is minimal Lagrangian. In this talk I will present a classification result for properly embedded CMC and CGC surfaces in Minkowski space, and show how harmonic maps from the complex plane to the hyperbolic plane play an essential role in the proof.

uk: вхід без авторизації

name: Harmonic maps to the hyperbolic plane and the classification of surfaces of constant curvature in Minkowski space

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: I will report on recent joint work with Rafe Mazzeo, Jan Swoboda and Frederik Witt on the asymptotic geometry of the Hitchin metric. This is the natural metric on the moduli space of Higgs bundles. We describe the difference to a more elementary semiflat metric, thus confirming part of a more general proposal of Gaiotto, Moore and Neitzke.

uk: вхід без авторизації

name: On the asymptotic geometry of the Hitchin metric


uk: Математика, природничі науки

description: A variation of twistor structures in the sense of Simpson, Sabbah and Mochizuki is a 1-parameter family of flat connections on a complex vector bundle with (to be chosen) additional data and constraints. Some version on rank 2 bundles turns up in the DPW method for constructing CMC surfaces. Another version of arbitrary rank is equivalent to Simpson's harmonic bundles, which are a generalization and weakening of variation of Hodge structures. A generalization of variation of Hodge structures which is a not a weakening, can be encoded as an integrable variation of twistor structures. Closely related versions of this are tt^* geometry (Cecotti-Vafa), TERP structures (Hertling) and noncommutative Hodge structures (Katzarkov-Kontsevich-Pantev). In the talk, I will discuss these structures in general, and in distinguished cases which arise in the theory of isolated hypersurface singularities. A good way to control them is given by the theory of meromorphic connections with irregular poles and their Stokes structures. I will sketch some results and some open questions.

uk: вхід без авторизації

name: Variations of noncommutative Hodge structures in general and in distinguished cases


uk: Математика, природничі науки

description: I will talk about a work in progress in collaboration with Christian El Emam, whose final motivation is to study the geometry of surface group actions on SL(2, C) regarded as the homogeneous space SO(4,C)/SO(3, C). I will mainly focussed on some analytical issues related to equivariant immersions. We will introduce the notion of first and second fundamental forms for an immersion and prove that they are solutions of a complex version of the standard Gauss Codazzi equation in the hyperbolic setting. We will discuss how far this theory can be regarded as a complex version of the Anti de Sitter geometry . In particular we will introduce a notion of left/right Gauss maps for an immersion that extends the corresponding notions in the Anti de Sitter setting. In the final part of the talk we will introduce the notion of minimal immersion in this context and will try to give a general description of the embedding data of minimal surfaces in terms of holomorphic objects.

uk: вхід без авторизації

name: Equivariant immersions of surfaces into SL(2, C) and complex metrics on surfaces


uk: Математика, природничі науки

description: Moduli spaces of stable vector bundles carry a natural Kähler structure, described originally in the Riemann surface case by Narasimhan and in the pioneering work of Atiyah-Bott. Such a Kähler structure is in many ways analogous to the Weil-Petersson metric on moduli spaces of Riemann surfaces, for which a deep relationship with the Liouville functional in Conformal Field Theory was established by Takhtajan and Zograf. In this talk I will describe work in progress on how the ideas of Takhtajan-Zograf can be adapted to vector bundles in three different settings: moduli of stable parabolic bundles in genus 0 and 1, moduli of semistable bundles in genus 1, and Jacobians. In all cases the main tool is an adaptation of the WZNW action of Conformal Field Theory---defined by twisting the so-called chiral models with a topological term---to a functional on singular hermitian metrics on a suitable holomorphic gauge. I will also describe briefly how the previous results can be generalized to moduli spaces of parabolic Higgs bundles.

uk: вхід без авторизації

name: WZNW actions, holomorphic gauges, and the Kähler structure of moduli spaces


The ends of the Hitchin moduli space

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Affine differential geometry and representations of surface groups


uk: Математика, природничі науки

description: Solutions of Hitchin's self-duality equations correspond to special real sections in the Deligne-Hitchin moduli space -- twistor lines. A question posed by Simpson in 1995 asks whether all real sections give rise to global solutions of the self-duality equations. An armative answer would allow for complex analytic procedure to obtain solutions of the self- duality equations. The purpose of my talks is to explain the construction of counter examples given by certain (branched) Willmore surfaces in 3-space (with monodromy) via the generalized Whitham flow. Though these higher solutions do not give rise to global solutions of the self- duality equations on the whole Riemann surface M, they are solutions on an open dense subset of it. This suggest a deeper connection between Willmore surfaces, i.e., a rank 4 harmonic map theory, with the rank 2 self-duality theory.

uk: вхід без авторизації

name: Higher solutions of Hitchin's self-duality equations


uk: Математика, природничі науки

description: Both the Higgs bundle moduli space and the moduli space of flat connections have a natural stratification induced by a C* action. In both of these stratifications, each strata is a holomorphic fibration over a connected component of complex variations of Hodge structure. While the nonabelian Hodge correspondence provides a homeomorphism between Higgs bundles and flat connections, this homeomorphism does not preserve the respective strata. The closed strata on the Higgs bundle side is the image of the Hitchin section (the Hitchin component) and the closed strata in the space of flat connections is the space of opers. In this talk we will show how many of the relationships between opers and the Hitchin component extend to general strata. This is based on joint work with Richard Wentworth.

uk: вхід без авторизації

name: Relations between Higgs strata and deRham strata


uk: Математика, природничі науки

uk: вхід без авторизації

name: Thermodynamic Bethe Ansatz for Nonabelian Hodge


uk: Математика, природничі науки

description: In their study of certain two-dimensional physical theories, Cecotti and Vafa discovered the tt*-equations. These are equations in terms of bundle data over the moduli spaces of these theories and their solutions are referred to as tt*-geometry. In this talk, based on joint work with Murad Alim and Laura Fredrickson, we study a particular class of tt*-geometry and match the tt*-equations with Hitchin’s equations. At the boundary of the corresponding moduli spaces of theories, parabolic structures naturally appear and we determine them explicitly in a wide range of examples. Finally, we comment on an oper limit of Hitchin’s equations in the parabolic framework.

uk: вхід без авторизації

name: tt*-geometry and parabolic Higgs bundles


uk: Математика, природничі науки

description: The moduli space of SL(n,C)-Higgs bundles over a Riemann surface admits a Hitchin fibration over the space of holomorphic differentials on the Riemann surface. In this talk, we focus on Hitchin fibers at (q2,0,...,0), that is, the fibers containing Fuchsian locus. We show a comparison theorem on the length spectrum between surface group representations in such fibers with Fuchsian ones, as a generalization of the SL(2,C) case shown by Deroin and Tholozan.

uk: вхід без авторизації

name: Representations in certain Hitchin fibers


uk: Математика, природничі науки

description: The pseudo-hyperbolic space Hp,q is a pseudo-Riemannian analogue of the classical hyperbolic space. In this talk, I will explain how equivariant maximal surfaces in H2,n are related to harmonic maps into some non-compact symmetric space (so in particular to Higgs bundles). This link provides a powerful tool to study maximal representations in rank 2 Hermitian Lie groups. This is a joint work with Brian Collier and Nicolas Tholozan.

uk: вхід без авторизації

name: Maximal surfaces in the pseudo-hyperbolic space


Convex tilings by triangles and more

uk: Математика, природничі науки

description: A triangulation of the sphere is combinatorially convex if each vertex is shared by no more than six triangles. In joint work with Philip Engel, we show that counted appropriately, the number of triangulations of the sphere with 2n triangles is the nth Fourier coefficient of a certain multiple of the Eisenstein series E10. Our method is based on Thurston's description of triangulations as lattice points in a stratum of sextic differentials. It generalizes in a straightforward way to show that the number of convex tilings of a sphere by squares or by hexagons also form the coefficients of a modular form. As a consequence, we reproduce formulas for Masur-Veech volumes of certain strata of cubic, quartic, and sextic differentials. Time permitting, I will describe an approach to counting problems in strata of differentials of all orders.

uk: вхід без авторизації


uk: Математика, природничі науки

description: We will recall the general loop group technique for primitive harmonic maps from Riemann surfaces to k-symmetric spaces and will give more concrete applications to such maps associated with the Kac-Moody algebra A2/2.

uk: вхід без авторизації

name: Primitive harmonic maps from Riemann surfaces to k-symmtric spaces and further applications to surface theory


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Mit radioaktiven Arzneimitteln Krebs bekämpfen

name: Eidgenössische Technische Hochschule Zürich (ETH Zürich)

addressCountry: CH

addressLocality: Zurich

addressRegion: Zurich


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Bioengineering of Human 3D Tissue Models for Clinical Translation


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Von neuen Elementen bis zum Alter des Universums


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Der Mensch als sein eigenes Ersatzteillager


uk: Комп'ютерні науки

uk: вхід без авторизації

name: E-Voting per Blockchain: Wie sicher ist das?


Revealing Jupiter’s Mysteries with Juno

uk: Комп'ютерні науки

uk: вхід без авторизації


Building a Robot Judge

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Was wir von Kartoffelchips lernen können


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Helping Crying Babies and Their Parents!


Natur und Kunst im Bilderbuch

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Beyond Bionics: Robotic Prostheses and the Brain


Wie wir mit Maschinen sprechen

uk: Комп'ютерні науки

uk: вхід без авторизації


Forschung naturgetreu fotografieren

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Die Haut ist das grösste Organ des menschlichen Körpers. Sie bildet eine wichtige Barriere zur Aussenwelt und schützt uns vor verschiedenen Bedrohungen, wie physischen Schäden, Wasserverlust und Infektionen. Sie hilft uns auch, unsere Körpertemperatur zu regulieren und bildet eine riesige Oberfläche für die sinnliche Wahrnehmung unserer Umgebung. SKINTEGRITY.CH ist ein schweizweites Verbundprojekt, das sich zum Ziel gesetzt hat, Krankheiten und Wundheilungsstörungen der Haut besser zu verstehen, zu diagnostizieren und zu behandeln. Anhand aktueller Beispiele zeigen wir, welche wichtigen Ergebnisse erzielt werden können, wenn das Knowhow von Grundlagenwissenschaftler*innen, klinische Expert*innen und Ingenieur*innen zusammengebracht wird. Wir berichten auch, wie durch diesen Verbund eine neue Generation von Wissenschaftlern ausgebildet wird, die interdisziplinäre Kenntnisse besitzen.

uk: вхід без авторизації

name: Interdisziplinäre Forschung ist die Hau(p)tsache


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Metamaterialien – Lego für Fortgeschrittene


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Planet Formation On-Board a Parabolic Flight


Neue Zellen für ein gesundes Gehirn

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Solar System in a Computer – Computer Simulations to Investigate Meteorites


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Regain Control: Fighting Incontinence with Stem Cells


Schöne neue Welt der Digitalisierung?

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Kann man mit Biotechnologie die Natur schützen?


Schneeflocken zählen aus dem All

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Does Terrifying Film Music Scare Us by Mimicking Human Screams?


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Before Science: Natural Phenomena in Ancient Religions


Data Science zum Anfassen

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Gemeinsam mehr erreichen - Mit Kollaboration zur Transformation

Universitätsbibliothek Bern

addressLocality: Bern

addressRegion: Bern


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: HOAD: Data Analytics für mehr Transparenz bei Open-Access-Transformationsverträgen


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Co-Publishing von Open Access-Monographien – Erfahrungen der Universität Stuttgart und dem KIT


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Diamanten teilen: Ergebnisse einer TU9-Standortanalyse für kollaborative Ansätze zur Förderung von Open-Access-Büchern


Open-Access-Publikationskosten @ JOIN²

uk: Фізика, Астрономія

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Математика, природничі науки

uk: Гуманітарні науки

uk: вхід без авторизації


uk: Фізика, Астрономія

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Математика, природничі науки

uk: Гуманітарні науки

uk: вхід без авторизації

name: Erweiterung der OpenAPC-Infrastruktur im Rahmen von openCost


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: DFG Open Access Publikationskosten: Anforderungen des Monitoring-Verfahrens


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Kollaboration im Kontext der FWF Open Access-Policy


uk: Комп'ютерні науки

uk: вхід без авторизації

name: IPT: Three ways you didn't think about sustainability

name: Eidgenössische Technische Hochschule Zürich (ETH Zürich)


Keynote - ubique

uk: Комп'ютерні науки

uk: вхід без авторизації


VIScon 2021 - Projects

uk: Комп'ютерні науки

uk: вхід без авторизації


Airlock - Secure Access Hub

uk: Комп'ютерні науки

uk: вхід без авторизації


Beekeeper

uk: Комп'ютерні науки

uk: вхід без авторизації


Building Secure Bluetooth IoT Products

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: How to create an online-marketplace with sustainably high margins


uk: Комп'ютерні науки

description: Mobile is already outdated. Instead, Spatial computing allows us to interact with real world objects in the surrounding space of the user and rely on context sensitive situations. In this talk, Daniel Neubig discusses the learnings and challenges Ergon had during the implementation of a new software and an Augmented Reality App to construction sites.

uk: вхід без авторизації

name: What comes after our smartphones? Spatial computing


Passwords - a trigger topic

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Practical guide to a compliant AI implementation


uk: Комп'ютерні науки

description: Infrastructure as code, a technique that treats infrastructure configuration the same way as code, has become widely adopted and is considered best practice to manage highly dynamic infrastructure, especially in the cloud. But the “as code” paradigm does not have to stop with infrastructure. Whether it is security policies, network rules, deployment pipelines, documentation or even architectural diagrams, the ability to express all elements of an IT system as code allows system engineers to apply established principles of software development (e.g. source control, reproducibility, maintainability, etc.) to literally all aspects of a software system. This talk introduces the principles of “Everything as code”, explains the fundamental ideas behind the approach and illustrates its many applications based on real-world examples from industry and the open source community. It also highlights the skill set that every computer scientist should acquire in order to participate in that paradigm shift.

uk: вхід без авторизації

name: Why "Everything as Code" changes everything


uk: Комп'ютерні науки

description: Is it possible to create machine learning models that always treat people fairly? And how can we convince the public that we use fair models?

uk: вхід без авторизації

name: The Road to Fair Machine Learning Models


uk: Комп'ютерні науки

description: From the Pyramids of Giza to the Gotthard Tunnel, the world of Project Management has always been stably classical, and then IT came along! With the special characteristic of software as a project delivery result, the possibility of a disruptively new approach opens up - Agile Project Management. Is IT taking advantage of its opportunities to revolutionize Project Management or are agile projects doomed to fail? We explore this question by comparing two major projects from the old and new world.

uk: вхід без авторизації

name: Unplanned Side Effects: How IT is enabling a revolution or missing its changes for Project Management


uk: Комп'ютерні науки

uk: вхід без авторизації

name: When hackers do good: The Future of Security Testing


uk: Комп'ютерні науки

description: Countless organizations across all sectors have been hit by large-scale and destructive cyber attacks. Increasingly sophisticated attacks occur more frequently, and attackers are leveraging previously unknown capabilities. Many cases quickly evolve into ‘extreme loss of technology’ crisis scenarios. Regular recovery measures have become ineffective in the light of such attacks. The common denominator of many of these catastrophic cyber attacks is that the attackers have commercialized their operating model, that they are highly professional, and that they actively seek to disable the attacked organization's defences in order to maximize the attack’s impact. In our talk, we will explore how organizations can adapt and improve their ability to recover from such catastrophic cyber attacks and achieve successful ‘Enterprise Recovery’.

uk: вхід без авторизації

name: Enterprise Recovery: Helping Organisations Recover: From Large-Scale Destructive Cyber Attacks


Founding a startup after ETH

uk: Комп'ютерні науки

description: Founding a startup after ETH can be both very fulfilling and challenging. How do you go about finding an idea? How do you find early adopters to test your idea with? In this session, Thomas talks about his journey after ETH as a co-founder of CareerFairy and the daily challenges in scaling a startup from Zurich to the world.

uk: вхід без авторизації