uk: Комп'ютерні науки

description: SIBELIUs uses an Open Data Cube to provide improved pasture monitoring capabilities in Mongolia and Kyrgyzstan to support their herding communities. SIBELIUs uses Open Data Cube (ODC) technology to provide improved pasture monitoring capabilities in Mongolia and Kyrgyzstan to support their large and economically significant herding communities. Satellite Earth observation provides an efficient means for monitoring environmental parameters, such as pasture, snow and drought, over large regions, which can facilitate improved pasture management decisions. The SIBELIUs team is working with key Mongolian and Kyrgyz stakeholders to develop ODC Technology to serve a wide range of users. SIBELIUS is supported by the UK Space Agency’s International Partnership Programme (IPP). In both Mongolia and Kyrgyzstan, SIBELIUs is using three existing networks to deliver the benefits of the project to the herding communities: (1) government agencies coordinating livestock and land use, (2) directly to the herders through social media, text messaging and television broadcasts, (3) through finance and insurance sectors.

uk: вхід без авторизації

name: Improving severe-weather resilience for Mongolian and Kyrgyz herding communities using earth observation imagery


Roman Karavia

type: Person

cs: Informatika

de: Informatik

fi: tietojenkäsittelytiede

uk: Комп'ютерні науки

en: Computer Science

fr: Informatique

da: Datalogi

es: Ciencias de la Computación

nl: Informatica

cs: Technické vědy

de: Ingenieurwissenschaften

fi: tekniikka

uk: Інженерія

en: Engineering Sciences

fr: Ingénierie

da: Ingeniørvidenskab

es: Ingeniería

nl: Engineering

description: Want to show Hubei Province (China) on an OpenMapTiles map? This talk shows how to extract region polygons for the entire planet from OpenStreetMap. Mapbox Vector Tiles are an established standard to create web maps with custom styling. They contain minimal data for rendering a base map, which includes boundaries between regions (countries and subdivisions) but not polygons of the regions themselves. So we can draw boundaries as needed, but we lack the data to highlight one specific region, which is a recurring need in data visualization. We wanted our highlighted regions to line up nicely with the boundaries on the base map, so we set out to extract compatible data from OpenStreetMap. The process, which uses various existing Open Source solutions and services (Overpass API, mapshaper, tippecanoe) will be presented in this talk. The result is an open dataset of regions which cover the entire planet. In our locator map tool, this dataset allows reporters and editors, who are not GIS experts, to highlight regions with a few simple clicks. These maps are routinely used in the online and print editons of the NZZ newspaper.

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: Extracting OpenStreetMap data for region highlights compatible with OpenMapTiles

type: Organization

name: Open Source Geospatial Foundation (OSGeo)

cs: Video

de: Video

fi: Video

uk: Відео

en: Video

fr: Vidéo

da: Video

nl: Video

es: Video


FOSS4G UK Online 2020 - Lightning talks

uk: Комп'ютерні науки

description: - E. Boyle, Using FOSS to develop a spatial and temporal visualisation of COVID-19 data: A visualisation of the spatial and temporal distribution of the 2020 COVID-19 pandemic using open technologies and resources. There are many visualisations on all media platforms of datasets relating to the distribution of the 2020 COVID-19 pandemic. Some are map-based, showing the geographic distribution of pandemic-related datasets (such as numbers of cases and deaths per country) and some are line and bar charts showing the variation of this data over time (such as curves of numbers of infections and recoveries). Hardly any of these visualisations attempt to combine a spatial and temporal approach to the data in the same visualisation. Almost none do it successfully. This lightning talk presents a web-based visualisation which attempts to do this, and a summary of the concepts and technical approaches used for its development. A FOSS and GIS-based approach to the data and software libraries used has been taken throughout. - R. Skujina, Stay home and innovate: redesigning an Earth Observation-fuelled accelerator supporting SMEs and start-ups: The PARSEC Accelerator, distributing €2.5 Million to SMEs and start-ups, enabled innovation from the safety of home as a response to the COVID-19. The PARSEC Accelerator, which will distribute €2.5 Million in equity-free funding for Earth Observation-based innovation, was one of the Copernicus-enabled business opportunities that Evenflow presented at the FOSS4G Bucharest in August 2019. After the successful start to 2020, with the PARSEC Open Call 1 attracting 348 SMEs and start-ups from 36 different countries and resulting in 100 competitive winners (#100PARSEC), the COVID-19 pandemic changed the rules of the game. The international team behind the accelerator committed to continue supporting innovation of SMEs, and therefore redesigned the first stage and the second Open Call of the accelerator. This enabled innovation to continue from the safety of home within the PARSEC ecosystem, and created a more open and borderless accelerator. - A. Cutts, awesome-earthobservation-code: Finding Earth Observation code is hard. awesome-earthobservation-code attempts to address this. It has over 270+ resources in one place. Earth Observation is one of the fastest growing areas of Geospatial today. Yet finding information about Earth Observation code (or even available commerical satellites) is harder than it should be. awesome-earthobservation-code attempts to address this. Built after a lunchtime scenefromabove discussion it currently has over 270+ resources in one place. I will set out some of the key information problems facing Earth Observation today and how awesome-earthobservation-code is a small step into building a bigger more vibrant community of collaborators. - S. Modekurty, OpenAQ: An open source platform to understand the world’s air quality: OpenAQ uses the power of open air quality data and open source tools to convene and empower communities around the world to fight air pollution. The OpenAQ platform aggregates real-time and historical geospatial air quality data from all over the world, and is entirely open source. It has over 500 million data points from 93 countries and serves 33 million API requests per month. The data have been used for a wide variety of applications, from air quality forecasts produced by NASA scientists to data-driven media reports by the general public. By providing this foundational data infrastructure, OpenAQ is able to convene people and organizations from across the globe to further raise awareness and develop innovative solutions to combat air pollution. The talk will give a technical overview of the platform, highlighting a new averaging tool being developed on top of the platform to get pollutant averages across various spatial and temporal resolutions.

uk: вхід без авторизації


Native support for vector tiles in QGIS

uk: Комп'ютерні науки

description: With QGIS 3.14, we have introduced native support for vector tiles in QGIS. It allows users to load, render, style and generate vector tiles in QGIS.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: SLYR is a QGIS plugin which has been developed by North Road to provide a route for the conversion of ArcGIS artefacts for use in QGIS. While the process is not yet 100% faithful to the original, it’s improving with regular releases. As well as a drag and drop facility for e.g. MXDs and layer files, the plugin also installs a set of tools in the Processing Toolbox which can be used independently and incoporated into processing models. The context for the demo will be MapAction’s use of SLYR to support interoperability between its work with Arc (mainly used in emergency missions) and QGIS (used in training and capacity building), and in particular to allow Arc products created in humanitarian response missions to be converted to QGIS for handover at the end of the mission to partners who are QGIS users. While the plugin has not yet been released as open source, North Road plan to do so once a specific funding threshold for development has been reached, with a six month delay.

uk: вхід без авторизації

name: ArcGIS to QGIS in One Easy Lesson with SLYR


uk: Комп'ютерні науки

description: A frequent query raised by new comers to QGIS (and other GIS systems) is “Why don’t my layers line up?”. This is usually followed by a long list of things they have vainly tried to make them line up, randomly changing the canvas and layer projections with no luck. This talk will discuss the basics of projections, coordinate reference systems and how this “magic” code affects the position of their data. Questions covered will include: + Why do you geographers force me to worry about this? + Why doesn’t it just work? + What is this Null Island you all keep going on about? + When should I change (override) the layer CRS? + What happens when I change the CRS of a layer and/or the canvas? + What is in this .prj file? Do I really need it? At the end of the talk new (and older) users will have more of an understanding of what projections are and how and why they need to deal with them.

uk: вхід без авторизації

name: What every GIS user should know about projections


uk: Комп'ютерні науки

description: Women in Geospatial+ is a professional network promoting gender-equality and diversity in geospatial field, aimed at women and other minority genders. Women in Geospatial+ started in March 2019 and grew into a vibrant and active community with more than 1200 registered members from all over the world and over 4000 followers on social media. The fast growing pace of this community is a sign that many of us still witness gender-bias in the workplace and more diversity-focused initiatives are needed. We provide our members with a safe platform for open and honest communication and exchange, sharing opportunities for career and personal development. To feature the work and achievements of women geospatial leaders, we hold regular in-person meetups at different geospatial events, run a mentorship program and have recently launched a speakers database. We will highlight key activities of our network, current facts and figures on diversity in geospatial and explain how to join and contribute to the community’s success and expansion. Let’s change the status quo together by creating a strong network of leaders and change-makers.

uk: вхід без авторизації

name: Women in Geospatial+ - Changing the status-quo by creating a strong network of Women in Geospatial+ leaders and changemakers


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: There are various methods known now for constructing more-or-less explicit metrics with special holonomy; most of these rely on assumptions of symmetry and/or reduction. Another promising method for constructing special solutions to look for metrics that satisfy algebraic curvature conditions. This often leads to a study of structure equations that satisfy an overdetermined system of PDE, sometimes involutive sometimes not, and the theory of exterior differential systems is particularly well-suited for analyzing these problems. In this talk, I will describe the ideas and the underlying techniques needed from the theory of exterior differential systems, illustrate the application in the most basic cases, and describe the results so far. A similar program has been implemented for finding explicit calibrated submanifolds of the associated geometries and, time permitting, I will describe some of this work and the current results.

uk: вхід без авторизації

name: Algebraically Constrained Special Holonomy Metrics and Second-order Associative 3-folds

name: Institut des Hautes Études Scientifiques (IHÉS)

addressCountry: FR

addressLocality: Bures-sur-Yvette

addressRegion: Île-de-France


uk: Математика, природничі науки

description: Minimal surfaces are ubiquitous in Geometry but they are quite hard to find. For instance, Yau in 1982 conjectured that any 3-manifold admitsinfinitely many closed minimal surfaces but the best one knows is the existence of at least two.In a different direction, Gromov conjectured a Weyl Law for the volume spectrum that was proven last year byLiokumovich, Marques, and myself. I will cover a bit the history of the problem and then talk about recent work with Irie, Marques, and myself: we combinedGromov’s Weyl Law with the Min-max theory Marques and I have been developing over the last years to prove that, for generic metrics, not only there are infinitely many minimal hypersurfaces but they are also dense.

uk: вхід без авторизації

name: Gromov’s Weyl Law and Denseness of minimal hypersurfaces


uk: Математика, природничі науки

description: Talk presented by P. PANSU The point of this talk is to introduce a polynomial differential operator which is an analogue of the classical real and complex Monge-Ampère equations. This operator makes sense on any symplectic manifold with a Gromov metric, and its solutions are exactly the functions obtained as upper envelopes of Lagrangian plurisubharmonic functions. Both the homogeneous and inhomogeneous Dirichlet problems for this operator are solved on Lagrangian convex domains, and the homogeneous result also holds for all other branches of the equation. Joint work with Reese Harvey

uk: вхід без авторизації

name: A Monge-Ampère Operator in Symplectic Geometry


uk: Математика, природничі науки

description: The Smale Conjecture (1961) may be stated in any of the following equivalent forms: • The space of embedded 2-spheres in R3is contractible. • The inclusion of the orthogonal group O(4) into the group of diffeomorphisms of the 3-sphere is a homotopy equivalence. • The space of all Riemannian metrics on S3with constant sectional curvature is contractible. While the analogous statement one dimension lower can be proven in many ways -for instance using the Riemann mapping theorem -Smale's conjecture turned out to be surprisingly difficult, and remained open until 1983, when it was proven by Hatcher using a deep combinatorial argument. Smale's Conjecture has a natural generalization to other spherical space forms: if Mis a spherical space form with a Riemannian metric of constant sectional curvature, then the inclusion of the isometrygroup into the diffeomorphism group is a homotopy equivalence. The lecture will explain how Ricci flow through singularites, as developed in the last few years by John Lott, Richard Bamler, and myself, can be used to address this conjecture. This is joint work with Richard Bamler.

uk: вхід без авторизації

name: Ricci flow, diffeomorphism groups, and the Generalized Smale Conjecture


uk: Математика, природничі науки

description: We show that the boundary distance function determine a simply connected surface with no conjugate points and that the lens data determine a non-trapping surface with no conjugate points. The novelty is that the manifold is not assumed to be « simple », i.e the boundary is not assumed convex. We also show new result on the geodesic ray transform when there is trapped set. This is joint work with Mazzucchelli and Tzou.

uk: вхід без авторизації

name: Boundary and lens rigidity for non-convex manifolds


Harmonic coarse embeddings

uk: Математика, природничі науки

description: The Schoen conjecture, recently proved by V. Markovic, states that any quasi-isometric map from the hyperbolic plane to itself is within bounded distance from a unique harmonic map. We generalize this result to coarse embeddings between two Hadamard manifolds with pinched curvature. This is a joint work with Yves Benoist.

uk: вхід без авторизації


uk: Математика, природничі науки

description: This is a joint work with Clara Aldana (Luxembourg) and Samuel Tapie (Nantes). In 1993, M. Gursky has shown a compactness result in

uk: вхід без авторизації

name: Compactness of conformal metric with a critical integrability assumption


uk: Математика, природничі науки

uk: вхід без авторизації

name: Noncollapsed Gromov-Hausdorff limit spaces with Ricci curvature bounded below


uk: Математика, природничі науки

description: We will provide an overview of some of the main results around manifolds with positive and non-negative sectional curvature and discuss established and evolving approaches to the area.

uk: вхід без авторизації

name: Positive curvature and beyond: A status report and future peek


uk: Математика, природничі науки

description: Filling a curve with an oriented surface can sometimes be "cheaper by the dozen".For example, L. C. Young constructed a smooth curve drawn on a projective plane in

uk: вхід без авторизації

name: Filling multiples of embedded curves and quantifying nonorientability


Optimal regularity for geometric flows

uk: Математика, природничі науки

description: Many physical phenomema lead to tracking moving fronts whose speed depends on the curvature. The level set method has been tremendously succesful for this, but the solutions are typically only continuous. We will discuss results that show that the level set flow has twice differentiable solutions. This is optimal. These analytical questions crucially rely on understanding the underlying geometry. The proofs draws inspiration from real algebraic geometry and the theory of analytical functions. Further developing these geometric techniques gives solutions to other analytical questions like Rene Thom's gradient conjecture for degenerate equations. We believe these results are the first instances of a general principle: Solutions of many degenerate equations should behave as if they are analytic, even when they are not. If so, this would explain various conjectured phenomena. Finally, the techniques should have applications to other geometric flows. If time permits, then we will discuss results about this. This is joint work with Bill Minicozzi.

uk: вхід без авторизації


uk: Математика, природничі науки

description: The rank of a hyperbolic manifold is the smallest number of generators of its fundamental group. McMullen conjectured that for all $k\geq 2$, the pointwise injectivity radius of a closed hyperbolic 3-manifold of rank at most k is uniformly bounded from above. We explain some methods which were introduced before and after the foundational work of Perelman to study these manifolds, and we show how these methods can be used to prove McMullen's conjecture in many cases including random 3-manifolds.

uk: вхід без авторизації

name: The geometry of 3 - manifolds before and after Perelman


uk: Математика, природничі науки

description: There are several questions about the behavior of Laplace eigenfunctions that are extremely hard to tackle and hence remain unsolved. Among the features that we don’t fully understand yet are: the number of critical points, the size of the zero set, the number of components of the zero set, and the topology of such components. A natural approach is then to randomize the problem and study these features for a randomized version of the eigenfunctions. In this talk I will present several results that tackle the problems described above for random linear combinations of eigenfunctions (with Gaussian coefficients) on a compact Riemannian manifold. This talk is based on joint works with Boris Hanin and Peter Sarnak.

uk: вхід без авторизації

name: Statistics of randomized Laplace eigenfunctions


1/4 The Self-Avoiding Walk Model

uk: Математика, природничі науки

description: The course will focus on rigorous results for the self-avoiding walk model on lattices, with a special emphasis on low-dimensional ones. The model is defined by choosing uniformly at random among random walk paths starting from the origin and without self-intersections. Despite its simple definition, the self-avoiding walk is difficult to comprehend in a mathematically rigorous fashion, and many of the most important problems illustrating standard challenges of critical phenomena remain unsolved. The model is combinatorial in nature but many questions about the stochastic properties of these random paths can be solved by combining nice combinatorial features with probabilistic techniques. In the course, we will describe some of the recent techniques developed in the area, including the use of discrete holomorphicity to understand the model on the hexagonal lattice.

uk: вхід без авторизації

name: Fondation mathématique Jacques Hadamard (FMJH)


2/4 The Self-Avoiding Walk Model

uk: Математика, природничі науки

uk: вхід без авторизації


3/4 The Self-Avoiding Walk Model

uk: Математика, природничі науки

uk: вхід без авторизації


4/4 The Self-Avoiding Walk Model

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Integrable QM Operators from Mirror Curves


CFT and Black Holes

uk: Математика, природничі науки

description: We will review progress in studying CFTs with a large number of degrees of freedom, and discuss how we can use it to learn something about gravity and black holes.

uk: вхід без авторизації


Mirror Symmetry and Feynman Integrals

uk: Математика, природничі науки

description: Based on work in progress with Spencer Bloch, Charles Doran, Matt Kerr, Audrey Novoseltsev

uk: вхід без авторизації


Anomalies, Inflow and Holography

uk: Математика, природничі науки

description: I will review the M5 anomalies in M-theory and their cancellation mechanism, and discuss its implications for the lower-dimensional super conformal field theories.

uk: вхід без авторизації


uk: Математика, природничі науки

description: I would like to promote the Self-Dual Yang Mills Theory as a possibly simplest non-linear conformal field theory in 4d with no supersymmetry. This field theory possesses UV divergences, but these do not spoil the conformal covariance: the effect of renormalization is that the coupling constant does not run, it is only a field renormalization which is needed. This results in a conformal invariance of the effective action under anomalous conformal transformations. I can give only a partial, but hopefully convincing proof of the latter. If the time permits I will also discuss the issue of conformal observables in this theory in relation with twistor geometry.

uk: вхід без авторизації

name: Conformal Properties of the Self-Dual YM Theory


uk: Математика, природничі науки

description: The elliptic genus of K3 surfaces encrypts an intriguing connection between the sporadic group Mathieu 24 and non-linear sigma models on K3, dubbed “Mathieu Moonshine”. By restricting to Kummer K3 surfaces, which may be constructed as Z2 orbifolds of complex 2-tori with blown up singularities, it has been possible to devise a framework in which the concept of symmetry surfing can be explored and tested in a concrete way. This talk focusses on what has been learned so far that supports the symmetry surfing idea when lifting the Kummer construction to the level of conformal field theory, with particular emphasis on quarter BPS states. Some of these states enter the elliptic genus with opposite signs thus cancelling each other when counted by this index, yet they carry interesting information that should help understand Mathieu Moonshine.

uk: вхід без авторизації

name: Mathieu Moonshine: Symmetry Surfing and Quarter BPS States at the Kummer Point


Degeneration, Geometry and Duality

uk: Математика, природничі науки

uk: вхід без авторизації


Coupling Holographic Universes

uk: Математика, природничі науки

description: I will discuss some recent progress on interacting-graviton theories in the context of the AdS/CFT correspondence.

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Supersymmetric Quantum Field Theories and the Swampland


The World as an Anomaly

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

description: Sinh-Gordon model is the simplest integrable model of QFT which is interesting, in particular, due to its relation to the Liouville model. In this talk I shall present hypothetical formulae for the diagonal matrix elements. The stress will be put on the UV limit and its relation to the Liouville three points functions. Based on joint work with Zoltan Bajnok.

uk: вхід без авторизації

name: Diagonal Finite Volume Matrix Elements in the Sinh-Gordon Model


uk: Математика, природничі науки

description: I will review the status of the theory of massive gravity, and will briefly discuss its applications in cosmology.

uk: вхід без авторизації

name: Field Theory for Massive Gravity and Cosmology

name: Institut des Hautes Études Scientifiques (IHÉS)


Space Time Actions from The World Line

uk: Математика, природничі науки

description: I will describe how the full non-linear equations of motion for all massless NS-sector fields of the string arise from world line quantization of the spinning particle. Somewhat surprisingly this includes the dilation which is often thought to be stringy in nature.

uk: вхід без авторизації


uk: Математика, природничі науки

description: The heat equation method in index theory gives an explicit local formula for the index of a Dirac operator. Its Lagrangian counterpart involves supersymmetric path integrals. Similar methods can be developed to give a geometric formula for semi simple orbital integrals associated with the Casimir operator of a reductive group, this computation being related to Selberg's trace formula. The analogue of the heat equation method is now a suitable deformation of the Laplacian by a family of Fokker-Planck operators. In joint work with Shu SHEN, we have also shown how to extend these formulas to orbital integrals involving general elements of the center of the enveloping algebra.

uk: вхід без авторизації

name: Fokker-Planck Operators and the Center of the Enveloping Algebra


uk: Математика, природничі науки

description: In the vicinity of a massive object of various scales (ranging from young stars to galactic nuclei), mass flow creates a spectacular structure combining a thin disk and collimated jet. Despite a wide range of scaling parameters, they exhibit a remarkable similarity that must be dictated by a universal principle. A generalized Beltrami condition has been formulated as a succinct representation of such a principle. The singularity at the center of the Keplerian rotation forces the flow to align with the “generalized vorticity” (including the effect of localized density and finite dissipation) which appears as an axle penetrating the disk – hence, the collimated jet is a Beltrami flow. An analytical expression of a disk-jet system has been constructed. Employing the Beltrami-Bernoulli flow configuration of disk-jet structure we apply our model for the analytic description of hydrodynamic jets from protostellar disks. For this purpose, we extend the standard turbulent viscosity prescription and derive several classes of analytic solutions using the flow parametrization in self-similar variables. Derived solutions describe the disk-jet structure, where, for the first time, jet properties are analytically linked with the properties of the accretion disk flow. These solutions can be used to analyze the astrophysical jets from protostellar accretion disks and link the properties of outflows with the local observational properties of accretion disk flows.

uk: вхід без авторизації

name: Generalized Beltrami-Bernoulli Flow Model for Astrophysical Disc-Jet Structure Formation


uk: Математика, природничі науки

uk: вхід без авторизації

name: New Dualities from Anomalies, and New Anomalies from Dualities


Reflection Operators in Integrable CFT

uk: Математика, природничі науки

description: The reflection operators are one of the simplest examples of the non-local integrals of motion in an integrable 2D CFT. They have many interesting applications, including for the description of the UV behavior of massive integrable perturbations of the CFT. In this talk, we’ll discuss the reflection operator in the context of the integrable structure that appears in the study of the quantum KdV theory. This operator is closely related to the Liouville reflection S-matrix. Briefly mentioned will be a new result concerning the full spectrum of this reflection operator, which was obtained recently within the framework of the ODE/IQFT correspondence. Based on Joint work with Gleb Kotousov.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Based on work in progress by M. Dodelson, SH. M. Watanabe and M. Yamazaki

uk: вхід без авторизації

name: Integrability, Theory Space, and My Debt To Samson Shatashvili


uk: Математика, природничі науки

description: At hadronic energy scales, quantum chromodynamics (QCD) requires a nonperturbative treatment to calculate physical observables. Lattice QCD is a nonperturbative framework that facilitates numerical simulation of the theory and is the only known systematically-improvable approach to calculate phenomenological relevant QCD parameters. I will discuss the lattice as a regulator for QCD, describe the current state-of-the-art and offer some perspectives for future directions.

uk: вхід без авторизації

name: QCD: Numerical Integration of a Quantum Field Theory


Multiplicative Higgs Bundles

uk: Математика, природничі науки

description: In this talk we'll establish the symplectic isomorphism between symplectic varieties obtained as (i) the symplectic leaves in the rational Poisson Lie group equipped with Sklyanin's Poisson structure, (ii) the moduli space of multiplicative Higgs bundles on P1 and (iii) the moduli space of periodic monopoles on R2xS1.

uk: вхід без авторизації


uk: Математика, природничі науки

description: I will review the properties and recent results for conformal fishnet theory (FCFT) which was proposed by O. Gurdogan and myself as a special double scaling limit of gamma-twisted N=4 SYM theory. FCFT, in its simplest, bi-scalar version, is a UV finite strongly coupled 4-dimensional logarithmic CFT dominated by planar fishnet Feynman graphs (of the shape of regular square lattice). FCFT inherits the planar integrability of N=4 SYM which becomes manifest in this case: the fishnet graphs can be mapped on the SO(2,4) integrable spin chain (A. Zamolodchikov, 1980). The D-dimensional generalization of FCFT, with SO(2,D) conformal symmetry can be also provided. A remarkable property of FCFT is the possibility of spontaneous symmetry breaking, which is not lifted by quantum corrections. I will also discuss the exact computation of certain anomalous dimensions and 4-point correlators, and of related fishnet Feynman graphs (of "wheel" or "spiral" type), using the quantum integrability tools: asymptotic and thermodynamic Bethe ansatz and quantum spectral curve.

uk: вхід без авторизації

name: Conformal Fishnet Theory in Any Dimension


Lattice Nonlinear Schroedinger Equation

uk: Математика, природничі науки

uk: вхід без авторизації


Anomalies: New Results and Applications

uk: Математика, природничі науки

description: I will review the concept of anomalies and its relationship with Symmetry Protected Topological Phases. I will also review various extensions of the concept of ‘’symmetry.’’ I will present applications to Yang-Mills theories in 2, 3 and 4 dimensions. These applications feature two extensions of the concept of symmetry: one is higher-symmetry and the other is "non-symmetry" topological defects.

uk: вхід без авторизації


uk: Математика, природничі науки

description: The theory of non smooth spaces with lower Ricci Curvature bounds has undergone huge developments in the last thirty years. On the one hand the impetus came from Gromov’s precompactness theorem and the Cheeger-Colding theory of Ricci limit spaces. On the other hand “synthetic” theories of lower Ricci bounds have been developed, based on semigroup tools (the Bakry-Émery theory) and on Optimal Transport (the Lott-Sturm-Villani theory). The Cheeger-Colding theory did not consider manifolds with boundary, while in the synthetic framework even understanding what is a good definition of boundary is a challenge. The aim of this talk is to present some recent results obtained in collaboration with E. Bruè (IAS, Princeton) and A. Naber (Northwestern University) about regularity and stability for boundaries of spaces with lower Ricci Curvature bounds.

uk: вхід без авторизації

name: Boundary regularity and stability under lower Ricci bounds


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

en: Information and Library Sciences

de: Geisteswissenschaften

uk: Гуманітарні науки

en: Humanities

@language: de

uk: вхід без авторизації

name: DATA TALKS #1: Datenbasierte Forschung (Teaser)


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: DATA TALKS #1: Statement von Prof. Mirco Becker


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: DATA TALKS #1: Statement von Prof. Dr. Ralph Ewerth


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: DATA TALKS #1: Statement von Dr. Wolfgang Stille


de: Humanmedizin/Gesundheitswissenschaften

uk: Медицина / Науки про здоров'я

en: Human Medicine / Health Sciences

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Quantifying the Immediate Effects of the COVID-19 Pandemic on Scientists

name: Centre for Science and Technology Studies (CWTS)

Technische Informationsbibliothek (TIB)

addressCountry: DE

addressLocality: Hanover

addressRegion: Lower Saxony


Bytes In Disguise: Q&A

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

description: On October 21st 2021, the European Commission approved the new Open Source Software Strategy 2020-2023 of the Commission. We will interview Evangelos Tsavalopoulos on this. In the interview we will ask the most important questions about this strategy.

uk: вхід без авторизації

name: European Commission Open source software strategy


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Blockchain Village - Blockchain for Cyber Defense: Will it be as good as you think?


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Blockchain Village - Is DeFi Ready for Prime Time


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Blockchain Village - Is DeFi Ready for Prime Time: Q and A


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Blockchain Village - Securing The Cosmos: How to Operate and Secure a Validator


uk: Комп'ютерні науки

uk: вхід без авторизації

name: VDF for Preventing DoS/ DDoS Attacks on Ethereum 2.0


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Blockchain Village - Attacking & Defending Blockchain Nodes


uk: Комп'ютерні науки

description: Der Vortrag beleuchtet die Einflüsse auf den geheimnisvollen Teil des Mobilfunks – Störquellen im Uplink und deren Auswirkungen auf die Mobilfunk-Kommunikation sowie Praktiken zum Aufspüren von HF-Störquellen. Die Feldstärke-Balkenanzeige eines Smartphones (die Downlink-Empfangsfeldstärke) ist nur die Hälfte der Wahrheit zur Bewertung einer Mobilfunkversorgung. Die andere Hälfte ist der weithin unsichtbare aber gegen Störeinflüsse hochempfindliche Uplink, die Richtung vom Endgerät zu den Basisstationen. In diesem Vortrag werden Uplink-Störquellen, deren Auswirkungen sowie Mess- und Analysemöglichkeiten erläutert.

uk: вхід без авторизації

name: Blockchain Village - Exploit Insecure Crypto Wallet


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Blockchain Village - 7 Phases Of Smart Contract Hacking


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: PostgreSQL is the first relational database which recognized the need of non-atomic data types to support developers of applications from science to Web. Jsonb in Postgres is the attractive feature for modern application developers, who want to work with json documents without sacrificing a strong consistency and ability to use all the power of proven relational technology. Finally, SQL world has recognized the NoSQL and released the new SQL-2016 standard, which includes specification of SQL/JSON data model and path language, as well as SQL commands for storing, publishing and querying JSON data. We will present the implementation of jsonpath, the path language for querying json in PostgreSQL and discuss possible extensions, such as new indexing mode for non-atomic data, which allows to index only specified parts, for example, those parts of jsonb which matches given jsonpath[s] to opclass.

uk: вхід без авторизації

name: Viva, the NoSQL Postgres !: Jsonpath - a query language for json

name: PGCon - PostgreSQL Conference for Users and Developers


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: VeniceDB, a Peta-byte scale real time analytics service running Postgres on Azure VeniceDB is a large scale OLAP service with a custom build of Postgres/Citus on Azure. Since the public talk at PostgresSV2018, the cluster has grown to 1PB to support Microsoft CoreOS executive decision dashboard that hosts all measures that cover from edge devices to cloud OS. VeniceDB has been in production for about a year, and went through a few major revisions while keeping the service running. During each revision, we keep tuning the data model and indexing to improve the data ingestion and query performance. We also migrated from Postgres10 to Postgres11, which helps to reduce the cluster cost by 30%. This talk covers why we chose Postgres and Citus as the foundation, and how we build a unified storage to serve various measure data needs. During our journey, we not only replaced traditional MapReduce based cubing jobs but also replaced a columnar storage cluster. We will share our perspectives on row storage vs column storage, and how we compare with other OLAP solutions like Druid, etc. and our wish list for future Postgres improvements.

uk: вхід без авторизації

name: VeniceDB: a Peta-byte scale real time analytics service running Postgres on Azure


Tuple Locking redesigned

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: In PostgreSQL, tuple locking is an important mechanism to maintain consistency in database. However, the current tuple locking system (also known as MultiXact locking system) comes with a few limitations, such as each new locker on a tuple combines the existing lockers along with itself and creates a new MultiXact entry in pgmultixact relation, thus increasing the pgmultixact relation size. Additionally, a 32 bit counter MultiXact Id is maintained for each MultiXact entry which requires efficient aging management, storage cleanup, and wraparound handling. In EnterpriseDB, as a part of new storage engine namely 'zheap', we redesigned the multi-locker mechanism to reduce the effects of afore-mentioned limitations. Since zheap is an undo-based storage, it stores the locking information of each locker in the separate undo records. Any transaction that intends to lock a tuple, it traverses all undo records corresponding to the page where the tuple is stored and collects all the lockers. Since, undo records are eventually discarded, 'zheap' multi-locker mechanism doesn't need any separate storage cleanup management. In this talk, we shall present the detailed design of locking mechanism in zheap and discuss how we've avoided a few limitations of current MultiXact system guided by some case studies.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Data encryption is one of the powerful methods to protect data from threats such as eavesdropping and theft. It is essential when storing confidential information such as credit card numbers, personal information of users, etc. Also, various data protection standards and regulations such as PCI DSS, GDPR, etc. require it. We have been researching how to make PostgreSQL more secure by implementing the built-in transparent data encryption for PostgreSQL. In this talk I will first introduce some studies about database encryption. Then, I'll provide some internal details of the implementing transparent data encryption and the performance evaluation result of the PoC based on our solution. It also covers the robust encryption key management, which is another important feature for data encryption. Various data protection standards and regulations such as PCI DSS, GDPR, etc. requires data encryption. There are methods to encrypt data stored in PostgreSQL, such as pgcrypto and file system level encryption using LUKS. However they don't satisfy the following properties of database encryption that are required by user and some security standards in practice: Transparent data encryption (TDE) Minimize performance impact Platform-independence We have been researching the built-in database encryption for PostgreSQL. Our solution consists of per-tablespace transparent data encryption while keeping minimize performance impact. We made a proof-of-concept code to evaluate our solution's usability and impact on the performance. In this talk, I will discuss about the principles of confidential information protection and database encryption methods. Then, I'll provide some internal details of built-in transparent data encryption of PostgreSQL and the evaluation results. It also covers the robust encryption key management, which is another important feature for data encryption.

uk: вхід без авторизації

name: Transparent data at rest encryption in PostgreSQL


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: So my talk may be about how the community handles i18n and l11n right now, how can we extend the translation experience with new online platforms (and some others). Which is absolutely harmless to nowadays processes. It just may be used together with old good tools, e.g. POEdit, KBabel etc. This is one of the interesting topics which is poorly lit at conferences and meetups. I'm talking about localization of PostgreSQL and other community software (possibly even commercial). Right now we're using https://babel.postgresql.org/ to manage translations, but I had excellent experience with online translation tools, such as transifex.com and crowdin.com. Which is absolutely free for open-source. I've even created PostgreSQL organization already, so I'm the boss ;) https://crowdin.com/project/postgresql So my talk may be about how the community handles i18n and l11n right now, how can we extend the translation experience with this new platform (and some others). Which is absolutely harmless to nowadays processes. It just may be used together with old good tools, e.g. POEdit, KBabel etc. There a lot of benefits, e.g. painless new language introducing, one translation memory for all products, ability to pay for translation (commercial soft), team collaboration (translators vs reviewers) etc. With online translation, you may involve new people in the community, e.g. new Ukrainian translation is in progress by high-school teenagers under my mentoring. But we also have GSoC project for students. Translation is easy mentoring and funny to do. Agenda: 1. Intro to l11n and i18n 2. Nowadays state of affairs 3. Demo of the localization process 4. Overview of the online platforms for open-source 5. Demo of the online localization process 6. Questions

uk: вхід без авторизації

name: Tower of Babel or How to turn an elephant into a polyglot


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Incremental View Maintenance (IVM) is a technique to maintain materialized views which computes and applies only the incremental changes to the materialized views to make refresh more efficient, but this is not implemented on PostgreSQL yet. In this talk, we will discuss what is necessary to implement IVM and our idea about the first version of IVM implementation on PostgreSQL. PostgreSQL has supported materialized views since 9.3. This feature is used to speed up query evaluation by storing the results of specified queries. One problem of materialized view is its maintenance. Materialized views have to be brought up to date when the underling base relations are updated. Incremental View Maintenance (IVM) is a technique to maintain materialized views which computes and applies only the incremental changes to the materialized views rather than recomputing the contents as the current REFRESH command does. This feature is not implemented on PostgreSQL yet. In this talk, after introducing some studies and discussions about IVM including our PoC (Proof of Concept) implementation, we will discuss what is necessary to implement this on PostgreSQL. For example, we have to decide how to extract changes on base tables, how to compute the delta to be applied to materialized views, when to maintain materialized views, and so on. Also, I will show our idea about the first version of IVM implementation on PostgreSQL.

uk: вхід без авторизації

name: Toward Implementing Incremental View Maintenance on PostgreSQL


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: A look at PostgreSQL transaction logging in historical POSTGRES and how it evolved in modern PostgreSQL, how the approach compares to other systems, and how it might evolve in future releases. Topics touched on include: transaction concepts demand paging and storage write ahead logs checkpointing recovery comparison with "ARIES" and with other RDBMSs undo log proposal rollback and recovery with undo logs MVCC and time travel with undo logs

uk: вхід без авторизації

name: Transactions: In PostgreSQL and other animals


The lost art of plpgsql

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: It is hard to believe, but plpgsql used to be a thing. Now lost in all the hype of REST APIs and JSON wizardry, the idea of doing server-side database functions gives most people the shivers. But as it turns out, doing things server-side can be pretty useful. So useful that Postgres 11 recently upped the plpgsql game by introducing support for true stored procedures. What does that mean for you? It's time to take another look at plpgsql and what new options are available inside everyone's favorite database. This talk aims to cover: A brief overview of postgres functions An equally brief look at plpgsql At least one slide on DO scripts A slightly more extensive look at the new stored procedure functionality A primer for advocating on using server side logic Always with the trade-offs Ok, plpgsql probably isn't going to take over the world, but its a handy toolset and one too many DBA's and Developers simply overlook in favor of more cumbersome solutions buried in their app code. We need to at least give it a fighting chance.

uk: вхід без авторизації


Temporal Databases: Theory and Postgres

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Temporal databases let you record history: either a history of the database (what the table used to say), a history of the thing itself (what it used to be), or both at once. The theory of temporal databases goes back to the 90s, but standardization has only just begun with some modest recommendations in SQL:2011, and database products (including Postgres) are still missing major functionality. This talk will cover how temporal tables are structured, how they are queried and updated, what SQL:2011 offers (and doesn't), what functionality Postgres has already, and what remains to be built. Many solutions exist for tracking changes to the database, e.g. for auditing or compliance. Often they use triggers to record changes in a separate schema, and better approaches also let you easily query for what the database said at a certain date. (For example see Magnus Hagander's 2015 talk "A Tardis for your ORM".) On the other hand, if you want to record a history of the thing itself, few solutions are available, and the problem is more complicated. The historical dimension can't be built automatically by triggers, but users need a way to edit old "versions" of the thing. They want to ask questions not only like "as of time t" but also preserving the historical changes across filtering, projecting, and joining. This kind of functionality is much harder to build without first-class support from your RDBMS. SQL:2011 includes support for both these dimensions, respectively "system time" and "application time", or even both together ("bitemporal"). We'll touch on system time but focus more on application time: how to declare a temporal table, how to set up temporal primary and foreign key constraints, how to insert and update it, and how to query it. My hope is to get the Postgres community aware of SQL:2011 temporal features so that we can start building support for them. We already have some great building blocks in place, especially ranges, exclusion constraints, and GiST indexes, so I'd like to explore how we can use those to support temporal functionality. I'd like to share my own work on a patch for temporal primary and foreign keys, and also briefly point out some work by others on writing temporal queries.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: In this report, I would like to share Avito’s experience in different cases of standby usage: problems and solutions in replication based horizontal scale-out; our implementation for solution to avoid stale reads from replica; cases highlighting possible problems while using standby with high request rate, applying DDL, receiving wal files from archive and handling some issues with technique of using few standbys in production and routing queries between them. DRP disaster recovery plans - to have synchronized standby/standbys with archive after crashes. I joined the Avito team five years ago. Now it is the second largest classified site in the world and its ads are stored in PostgreSQL databases. Last year, I gave a talk at PgCon 2018 that explained in details how our recovery use cases around Londiste (PGQ in general) in distributed data processing could be switched to new Logical Replication subsystem in PostgreSQL 10. In this talk, I will raise the topic of “simple” replication based on horizontal scale-out. One part of this presentation aims to describe the basics of technique when running applications powered by PostgreSQL are offloading read operations to read only replicas. It is a pretty good high-impact and low-effort win for scalability, but not without challenges. There is a possibility of stale reads. Even systems using read replicas without any techniques for mitigating stale reads will produce correct results most of the time, but for us “most of the time” isn’t good enough. Another part of my report is about few pitfalls that many people are not aware of, while others have simply accepted the risks. These problems can happen when you use standby with high request rate/ apply DDL/ receive wal files from archive/ promote one of your standbys after primary crash without saving consistency of your archive and other standbys. Over the years of constantly using physical replication, we gained extensive experience, rethought a lot, implemented our own workarounds, archive and restore commands and disaster recovery plans in case of crashes in distributed data processing systems. All these efforts and its results are worth being shared with who plans and proceeds PostgreSQL’s enterprise use.

uk: вхід без авторизації

name: Standby in production: scaling application in second largest classified site in the world.


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Reasons for running your own Buildfarm Server include that you maintain your own fork, and that you want to be able to run tests with uncommitted patches. Recent developments make doing all this a lot easier. There is a now a complete vagrant recipe for setting up an instance. The buildfarm itself now regularly creates a sample of its data suitable for populating a test buildfarm instance. And the Buildfarm client now contains support for testing arbitrary branches, including things like uncommitted/unmerged patches. This talk is about how to use all these shiny new tools. The PostgreSQL BuildFarm's original purpose, still valid today, was to ensure that committed patches build and test cleanly on a wide variety of platforms. We have members with a very wide variety of Architectures, Operating Systems, and so on. No non-distributed build system is likely to provide such coverage. However, there have long been requests to support testing other repositories, and to test patches prior to their being committed/merged. Recent developments have made both of these much easier. Although the code for running the buildfarm server has long been public, there has never been a deploy script available up to now. The new vagrant setup contains a full deploy script for Debian Stretch (which is what the community's buildfarm server runs on). This setup could easily be adapted to other platforms. It includes a download of anonymized sample data so that you can see how it runs without having to provide any data yourself. We'll examine how to get the clients to build the branches you want. We will also explain how to set up a git repository with unmerged branches, and how to get the buildfarm client to build those branches, and how to remove them when they are no longer needed.

uk: вхід без авторизації

name: Running your own buildfarm server, and testing your own patches


The Future of Postgres Sharding

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Database sharding involves spreading database contents across multiple servers, with each server holding only part of the database. While it is possible to vertically scale Postgres, and to scale read-only workloads across multiple servers, only sharding allows multi-server read-write scaling. This presentation will cover the advantages of sharding and future Postgres sharding implementation requirements, including foreign data wrapper enhancements, parallelism, and global snapshot and transaction control. This is a followup to my Postgres Scaling Opportunities presentation.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Pluggable table access methods (pluggable storage) PostgreSQL supports only single type of table unlike many other RDBMS. In this talk, it will be discussed need for pluggable storage and its benefits and next steps of pluggable storage in future PostgreSQL versions. Pluggable storages is hot subject in PostgreSQL development. The period of heated debates about whether we need them is over. Skepticism about pluggable storages, based on concern that they may be source of inconsistent behavior. It became widely understandable that pluggable storages are needed at least for an alternative MVCC implementation. And that is one of way-points for pluggable storages interface design. This talk will cover following subjects: overview of pluggable storages interface; changes in PostgreSQL core required to implement this interface; current and potential implementations of pluggable storages including heap with undo-log and in-memory engines; current state of patch-set and prospective of its commit further development of interface allowing more possibilities in pluggable storages (columnar, index-organized, LSM and so on).

uk: вхід без авторизації

name: Pluggable table access methods (pluggable storage): pluggable storage


Pluggable Table Storage in PostgreSQL

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: For PostgreSQL 12 we have worked hard at making table storage pluggable, i.e. allowing to store table data in different forms than PostgreSQL's current heap. This talk will explain: Why we think it's important to make postgres' storage pluggable how the new API works what types of table stores can be implemented, and what types are not yet possible how the limitations of pluggable storage can be addressed in future versions of PostgreSQL

uk: вхід без авторизації


Streaming Analytics with PostgreSQL

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: PipelineDB is a PostgreSQL extension that empowers time-series aggregations. Using a new type of relation known as a “Continuous View,” PipelineDB extends PostgreSQL utility into the realm of streaming analytics. A Continuous View is similar to a conventional view, except that it can source from data streams instead of tables. As stream data arrives, the values of the view are continuously updated. This has vast application in clickstream data analysis, systems monitoring and A/B testing, among others. Continuous Views can be constructed to operate over the entire data stream, or over a sliding window. All of the power of PostgreSQL analytic functions are available for use in Continuous Views, as well as additional functions that are specific to streaming data analytics. PipelineDB transforms PostgreSQL into a very viable and capable technology for streaming analytics. It is an alternative to Kafka Streams, with the huge advantage that PipelineDB streaming analytics are constructed in SQL, whereas the latter requires Java coding experience. Data Analysts generally live in a SQL world — it’s what they know. PipelineDB empowers analysts to construct their own streaming analytics via SQL instead of relying on Java engineers to code up the logic, making it scale. PipelineDB also allows an organization to leverage its existing PostgreSQL admin resources into its streaming analytics infrastructure, which can be a significant cost savings. This talk is introductory, but those attending will come away with a good sense of what PipelineDB is, how it works, and why it should be considered. Specific topics include: PipelineDB as an extension to PostgreSQL An introduction to Streams and Continuous Views Applications PipelineDB in Kafka (setup, etc.) Comparison to alternatives (Kafka Streams, Spark) PipelineDB in the cloud (sharding and elasticity) Streaming analytics are becoming an important part of data strategy. PipelineDB turns PostgreSQL into the only RDBMS that can provide true utility in streaming analytics. Anyone who is involved with PostgreSQL in an organization that is pondering their streaming analytics strategy will benefit from this talk.

uk: вхід без авторизації


PGCon 2019 - Opening Sessions

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: The usual opening session and review of things to come.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Odyssey is new PostgreSQL connection pooler designed for the high-load environment. It can significantly scale processing performance by specifying the number of additional worker threads. This allows to increase SSL/TLS performance and provide more balanced pooling control using by sharing global server connection pools. Odyssey is PostgreSQL connection pooler designed from scratch to provide multi-threaded processing. Each worker thread is responsible for authentication and proxying client-to-server and server-to-client requests. All worker threads are sharing global server connection pools. It tracks a transaction state and in case of unexpected client disconnection can emit automatic Cancel and do Rollback of an abandoned transaction, before putting server connection back to the server pool for reuse. Odyssey allows defining connection pools as a pair of Database and User. Each defined pool can have separate authentication, pooling mode, and limits settings. Odyssey has a sophisticated asynchronous multi-threaded architecture which is driven by custom made coroutine engine. One of the main goal was to make codebase understandable for new developers and to make an architecture easily extensible for future development. Ideas behind the coroutine design and more detailed features overview will be presented during the talk.

uk: вхід без авторизації

name: Odyssey: Advanced multi-threaded PostgreSQL connection pooler and request router.


nbtree: An architectural perspective

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Many PostgreSQL users have a basic understanding of how Postgres nbtree indexes work internally (e.g., how the structure is maintained, high level details of how a new level is added to the tree, the role of VACUUM in garbage collection). A smaller number have some understanding of advanced topics (e.g., details of Lehman & Yao's B-Link technique, details of crash recovery). Even an experienced backend hacker could be forgiven for concluding that this is all well explored territory, leaving little room for improvement, since all the important components are already in place. This view of things is based on a correct premise, and yet cannot explain why nbtree doesn't perform well with certain specific real world workloads. For example, there is an excessive amount of nbtree index bloat created by the industry standard TPC-C benchmark, despite the fact that TPC's transactions rarely update indexed columns, and therefore handily avoid so-called "write amplification". Certain pieces are missing. Code enhancements (authored by the speaker) that will appear in PostgreSQL 12 will significantly improve matters for affected workloads. In some ways, this work is based on a return to decades old fundamentals. In other ways, it is based on practical experience, involving analyzing real-world index structures in an effort to learn where problems may lie. This talk will cover: • A review of the design of nbtree, especially its high level goals. • The importance of thinking in terms of invariants — the rules underlying what belongs where in the index. • Interesting ways in which nbtree exceeds what is truly required by the invariants, and how that can be exploited to improve performance. • Possible future work aimed at reducing CPU cache misses while descending a B-Tree. • The big picture — how all these techniques are complementary, and worth more than the sum of their parts.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: A regular feature, PGCon will have a Lightning talks session, with presentations on diverse topics. The format remains essentially the same: in a one hour period, audiences are entertained and informed by a rapid fire series of short talks on interesting new or on-going work by individuals or groups. Slides aer permitted, but not obligatory; pictures are highly recommended. Topic areas include new open source software projects, works in progress for future releases of existing projects, student projects, etc. Lightning talks topics this year may make good conference papers next year! The number of slots is limited, and experience suggests there will be more takers than slots. Sign up well in advance to be assured a spot. Please subscribe to the PGCon announce mailing list and wait for the call to go out for submissions. NOTE: there is no "2" below because that lightning talk did not include slides.

uk: вхід без авторизації

name: PGCon 2019 - Lightning Talks: Short sharp descriptions of short topics


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: There are situations where an existing database mechanism doesn't provide sufficient methods to determine the exact work being performed. An example of such situation is GIN index rebuilds as a result of the fastupdate mechanism and slow computation of query plans. Due to wrongly selected systems timers. With the help of DTrace, we will take a look on the Postgres internals and we show how a system administrator can clearly identify the root cause of a hanging insert and the slow computation of the query plans. DTrace is a dynamic tracing framework created by Sun Microsystem and available in FreeBSD, NetBSD, and MacOS. Dtrace is a powerful tool which allows software developers and administrators measure performance and trace their applications using advanced scripting language - D. Before entering the beautiful world of Postgres during this talk we will discuses the basics of it. Gin in Posrgres stands for Generalized Inverted Index and should be considered as a genie, not a drink. Generalized means that the index does not know which operation it accelerates. Having to do multiple searches/insertions when the same key appears in multiple heaps becomes costly during bulk insertions hence a fast update feature has been developed that maintains a pending list of entries delaying the index rebuilds in time. Usually, the pending list is merged with the main btree by the vacuum process but it can also happen in other situations. Currently, the PostgreSQL database lacks a mechanism allowing a DBA to know when exactly this situation occurs and how long it took. This can lead to seemingly hanging INSERT and a DBA scratching his head not knowing what causes the stall. Using DTrace we can show exactly when this rebuild happens, how long it took and how a DBA can script this in D expanding his toolbox for the future - all without rebuilding the database.

uk: вхід без авторизації

name: Let's (D)Trace Postgres: tracing the madness


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: SQL parser is an important subsystem in PostgreSQL because it understands SQL queries and turns it into a machine readable form so that subsequent subsystems can easily handle user's SQL. In this talk I will explain the internal of SQL parser through an experience in porting it to other applications. PostgreSQL query processing architecture consists 4 steps: parser, rewriter, optimizer and executor. The parser is a PostgreSQL internal module to parse the SQL from application and returns an internal PostgreSQL parse tree. The SQL parser is divided into two pieces: raw parser which is responsible for syntactic analysis of SQL, and analyzer which adds semantics information by looking up system catalogs. In this talk, firstly I will explain the internal of the SQL parser. Next, because there are many applications which want to have an SQL parser, I will show you how to port the raw parser to an application by using Pgpool-II as a concrete example.

uk: вхід без авторизації

name: Introducing PostgreSQL SQL parser: Use of PostgreSQL Parser in other Applications


Learning to Hack on Postgres Planner

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: his talk will cover the process of debugging a bad plan starting from the explain output through hacking in a fix and recompiling the database. Topics covered will include: characteristics of a plan and how these map to components in Postgres code, strategies for producing a minimal repro, simple heuristics for developing a reference plan, using the debugger along with several GUCs to examine the plan tree throughout planning, and, finally, adding in your own code. The intro to query optimization topics covers the basic stages of planning and how those are represented in the form of a query tree and, ultimately, plan tree in Postgres' query optimizer. The case study uses a simple example of a "bad" plan to show how to determine where to add code to modify the behavior of planner. The first few and last slide will be used to discuss how people learned to hack on Postgres planner and what most helped them.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: A discussion of ways to improve the documentation ecosystem for PostgreSQL inside core, other sources and help in citing those sources in outside forums. The documentation for PostgreSQL is quite extensive, but that can work against us when attempting to cite a specific feature or function. We are left with telling information-seekers here's a link to a very long page, look for the $SEARCH_TERM in that page. Some users seem to learn best when first given a concrete example of the usage of a command or feature, and only then will the abstract documentation make sense. This talk proposes a number of incremental changes that could improve the usability and durability of our documentation in both core and the ancillary wikis. Such as examples with date/version context, flagging new features, and persistent reference anchors. It will also propose some standards for citation of sources when making references to them in outside forums like StackExchange.

uk: вхід без авторизації

name: In aid of RTFM: Improving our documentation


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: PostgreSQL is unique in its way of handling incoming patches and feature proposals with its commit fest system, and getting a feature accepted or rejected can be hard to accept for newcomers which perhaps do not have a lot of insight about how the community works. This presentation covers the process community uses to handle patches and how the development of PostgreSQL happens, from the tools in place to the set of implicit rules used by seasoned hackers. With this presentation, any newcomer to the community will get a good insight of how to work with other members, getting at the end potentially something committed. Because at the end, investing in PostgreSQL takes a certain initial investment but the long-term prospects are excellent for anything depending on PostgreSQL.

uk: вхід без авторизації

name: How to get a feature committed?: Community rocks


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: At Zalando we run PostgreSQL at scale: a few hundred database clusters in sizes from a few megabytes up to 10 terabytes of data. What is a bigger challenge than running a high-OLTP multi-terabyte PostgreSQL cluster? It is the migration of such a cluster from the bare-metal data center environment to AWS. There were multiple problems to solve and questions to answer: Which instance type to choose: i3 with ephemeral storage or m4/m5/r4 + EBS volumes? Should we give Amazon Aurora a try? Direct connection from AWS to the data-center is not possible. How to build a replica on AWS and keep it in sync if VPN is not an option. The database (primary and replica) is used by a few hundred employees for ad-hoc queries; ideally, they should retain access through the old connection url. How to do backups of such a huge DB on AWS? We should be able to switch back to the data-center if something goes wrong. In this talk, I am going to provide a detailed account of how we managed to successfully solve all these problems.

uk: вхід без авторизації

name: Highway to Hell or Stairway to Cloud?: How we migated our biggest cluster to AWS


High Performance pgBackRest

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: pgBackRest is open source software developed to perform efficient backup on PostgreSQL databases that measure in tens or hundreds of terabytes and/or generate high WAL volume. pgBackRest supports a robust set of performance features, including: parallel backup/restore, delta restore, parallel asynchronous archiving, partial/failed backup resume, backup from standby, and more. This talk by the primary maintainer will focus on: Performance features of pgBackRest. Practical configuration examples. Parallel backup/restore and archiving implementations. The attendee should gain a good understanding of which performance features are useful in a variety of circumstances.

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: In this talk I want to present current developments in the world of graph databases and discuss how we could extend and evolve PostgreSQL to work well with graph data. Graph databases are a major database paradigm next to relational databases, object databases, hierarchical databases, and so on. While there are popular standalone graph database products, some vendors from other fields including traditional SQL as well as NoSQL have begun to extend their products with graph data capabilities and interfaces. PostgreSQL has been successfully extended to support nonrelational uses such as document stores, so it is worth discussing whether and how graph database capabilities could also be integrated into PostgreSQL. At the moment, the graph database world suffers from an overabundance of different query languages. There are, however, efforts underway to unify some of these and standardize them under the umbrella of standardization organizations such as W3C and ISO. This would make it easier for products such as PostgreSQL, whose primary focus is not graph data, to add support for graph data query languages without having to worry about competing languages and standards. I'll try to sort through this and show what is currently going on in graph database languages.

uk: вхід без авторизації

name: Graph Databases: Introduction, Standardization, Opportunities


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Currently the query planner in PostgreSQL generates plan that is supposed to be executed on a single-node PostgreSQL. What if we want to run queries in the MPP (massively parallel processing) way? Greenplum Database is an open source MPP database with PostgreSQL kernel inside. In this talk, I will introduce how Greenplum Database generates distributed plan for PostgreSQL. Greenplum Database is an open source MPP (massively parallel processing) database with PostgreSQL kernel inside. It is essentially several PostgreSQL disk-oriented database instances acting together as one cohesive database management system (DBMS). Particularly, the optimizer in Greenplum Database is based on PostgreSQL’s optimizer, which takes a query tree as input, examines each of possible execution plans and ultimately selects the execution plan that is expected to run the fastest. In order to meet the MPP environment, the optimizer in Greenplum Database has been modified and enhanced to support the parallel structure of Greenplum Database. It produces such plan that is able to be executed simultaneously across all of the parallel PostgreSQL database instances. As a result, the implementation of optimizer in Greenplum Database differs from that in PostgreSQL in several aspects. This talk will introduce these differences in optimizer between Greenplum Database and PostgreSQL, and illustrate how Greenplum Database achieves and optimizes a plan for parallel environment.

uk: вхід без авторизації

name: Generating distributed plan for PostgreSQL

name: PGCon - PostgreSQL Conference for Users and Developers


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Postgres relies heavily on an extension ecosystem, but that is almost 100% dependent on C; which cuts out developers, libraries, and ideas from the world of Postgres. postgres-extension.rs changes that by supporting development of extensions in Rust. Rust is a memory-safe language that integrates nicely in any environment, has powerful libraries, a vibrant ecosystem, and a prolific developer community. Rust is a unique language because it supports high-level features but all the magic happens at compile-time, and the resulting code is not dependent on an intrusive or bulky runtime. That makes it ideal for integrating with postgres, which has a lot of its own runtime, like memory contexts and signal handlers. postgres-extension.rs offers this integration, allowing the development of extensions in rust, even if deeply-integrated into the postgres internals, and helping handle tricky issues like error handling. This is done through a collection of Rust function declarations, macros, and utility functions that allow rust code to call into postgres, and safely handle resulting errors.

uk: вхід без авторизації

name: Deep Postgres Extensions in Rust: postgres-extension.rs


PGCon 2019 - Closing Sessions

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Five years after removing SnapshotNow, PostgreSQL still has very little in the way of DDL that can execute concurrently with user queries, and many of the facilities that do exist have significant and sometimes painful limitations. In this talk, I'll give an overview of the problems that have stymied previous attempts to reduce lock levels and design new concurrent DDL facilities. The removal of SnapshotNow provides only a very limited guarantee about how sane catalog lookups can be assumed to be in the presence of concurrent DDL. The heavyweight lock manager, the shared invalidation system, and the relcache are interrelated subsystems with complex interactions whose basic design presupposes that concurrent DDL does not exist. Query planning relies on certain information remaining static between plan time and execution time both for both efficiency and correctness. Deadlock hazards hinder efforts to keep the time for which strong relation locks are held to a minimum. I'll discuss these and other problems that make implementing concurrent DDL correctly an exceptionally hard problem within the PostgreSQL infrastructure.

uk: вхід без авторизації

name: Challenges of Concurrent DDL: Why is this such a hard problem, and is there anything we can do about it?


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Database systems don't just slow down in a clear, linear way. They reach a certain point and start failing, often very suddenly and surprisingly. This talk is about some of the most common scaling "discontinuities" in PostgreSQL, and how to plan for them and mitigate them. Why is SERIAL a bad primary key on high-insert-rate tables? What happens when autovacuum can't keep up? How do you know you don't have enough memory for your queries? What happens when a query that worked just fine before suddenly has a horrible plan? Drawn from real-life examples, we'll go over these and show how to fix them… and avoid them in the first place.

uk: вхід без авторизації

name: Breaking PostgreSQL at Scale: Before you can fix it, you need to know how it breaks.


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Selecting and using the correct memory context is something I have seen many folks struggle with when writing C-language extensions in PostgreSQL. This talk will set you on solid footing in this regard. Areas covered will include an overview of how memory is allocated, the concept of memory contexts as defining lifecycles for memory allocations, how these are structured, and which memory contexts should be selected in which scenarios. Best practices, as well as some advanced topics such as how memory contexts are used to cache query plans in SPI-based user-defined functions will be covered. One thing I have seen even competent C programmers struggle with when creating C-language extensions is the question of how to determine the proper lifecycle of memory allocated in the extension itself. This talk is intended to provide a number of points to get beginners the direction needed to safely utilize PostgreSQL's memory management when writing C-language extensions. Areas covered will include: How memory is managed in PostgreSQL. Memory Contexts and Lifecycles The Most Commonly Used Memory Contexts Context Matters: What Happens If You Use The Wrong One Best Practices An Advanced Example: How SPI Cached Plans Work By the end of the talk, participants should have a clear understanding of how to work confidently with PostgreSQL's memory management subsystem, how to catch errors, and create fully robust C extensions.

uk: вхід без авторизації

name: An Introduction to Memory Contexts: Common Questions, Answers, and Best Practices


Advanced Authentication

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: PostgreSQL supports a number of different authentication mechanisms and while many of them are quite simple and easy to use, the enterprise-level authentication systems require setup beyond PostgreSQL and a deeper understanding of how authentication works. This talk will cover implementing the two most prevelant enterprise authentication schemes- Kerberos/GSSAPI (used extensively by universities and businesses, and is the authentication system for Microsoft Windows) and Client-Side Certificates / SSL (used by many governments and high security systems). We will go into detail on how to integrate PostgreSQL into these enterprise authentication schemes, and cover the different options and limitations

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Fondation mathématique Jacques Hadamard (FMJH)

name: 4/4 On the Mathematical Theory of Black Holes

name: Institut des Hautes Études Scientifiques (IHÉS)


uk: Математика, природничі науки

uk: вхід без авторизації

name: 3/4 On the Mathematical Theory of Black Holes


uk: Математика, природничі науки

uk: вхід без авторизації

name: 2/4 On the Mathematical Theory of Black Holes


uk: Математика, природничі науки

description: The gravitational waves detected by LIGO were produced in the final faze of the inward spiraling of two black holes before they collided to produce a more massive black hole. The experiment is entirely consistent with the so called Final State Conjecture of General Relativity according to which generic solutions of the Einstein vacuum equations can be described, asymptotically, by a finite number of Kerr solutions moving away from each other. Though the conjecture is so very easy to formulate and happens to be validated by both astrophysical observations as well as numerical experiments, it is far beyond our current mathematical understanding. In fact even the far simpler and fundamental question of the stability of one Kerr black hole remains wide open. In my lectures I will address the issue of stability as well as other aspects the mathematical theory of black holes such as rigidity of black holes and the problem of collapse. The rigidity conjecture asserts that all stationary solutions the Einstein vacuum equations must be Kerr black holes while the problem of collapse addresses the issue of how black holes form in the first place from regular initial conditions. Recent advances on all these problems were made possible by a remarkable combination of geometric and analytic techniques which I will try to outline in my lectures.

uk: вхід без авторизації

name: 1/4 On the Mathematical Theory of Black Holes


uk: Комп'ютерні науки

description: Presentations from the DEF CON 27 AI Village

uk: вхід без авторизації

name: AI Village - A Tutorial on Hacking Facial Recognition Systems


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Disinformation: Its the Thought that Counts


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Regulating AI and Algorithms: Lessons from safety and security certifications and audits


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Exploratory Data Analysis: Why and How (in Python)


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Clairvoyance: concurrent lip-reading for the smart masses


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - A 'buyers guide' to the market promise of automagic AI-enabled detection and response


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Behavioral Biometrics and Context Analytics: Risk Based Authentication Re-Imagined


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Automated Injection and Removal of Medical Evidence in CT and MRI Scans


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Backdooring Convolutional Neural Networks via Targeted Weight Perturbations


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - From Noisy Distorted data sets to excellent prediction model


uk: Комп'ютерні науки

description: Presentations from DEF CON 27 AI Village

uk: вхід без авторизації

name: AI Village - Machine Learnings Privacy Problem


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Machine Learning Static Evasion Competition


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Loss Is More! Improving Malware Detectors by Learning Additional Tasks


AI Village - Misinformation Keynote

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Securing your kubeflow clusters


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Deepfakes, Deep Trouble: Analyzing the Effects of Deepfakes on Market Manipulation


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Fighting Malware with Deep Learning video


AI Village - Opening Remarks

uk: Комп'ютерні науки

description: Presentations from DEF CON 27 AI Village opening remarks

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Seeing is deceiving: The rise of AI synthesized fake media


AI Village - Deep Fakes Panel

uk: Комп'ютерні науки

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - Datasciencery by the Splunk Field


uk: Комп'ютерні науки

uk: вхід без авторизації

name: AI Village - How to Get over your malicious ex(tensions) using deep learning


Ethics Village - Coffee Talk

uk: Комп'ютерні науки

description: Presentations from the DEF CON 27 Ethics Village

uk: вхід без авторизації


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Ethics Village - Ethical Issues in Cyber Attribution


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Ethics Village - Void If Removed: Securing Our Right to Repair


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Ethics Village - Is It Ethical to Work On Autonomous Weapon Systems?: Campaign to stop Killer Robots


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Ethics Village - Law Professor Round Robin


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Ethics Village - A Rant on Disclosure: How to get fired doing the right thing


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Ethics Village - Teaching Consulting Pentesting and Ethics: Lessons learned from a Running a National Penetration Testing Competition


uk: Комп'ютерні науки

uk: вхід без авторизації

name: Ethics Village - Who is Tracking Your Body Health Apps and Your Privacy


Tag side attacks against NFC

uk: Комп'ютерні науки

description: This talk covers tag-side attacks against NFC communication protocols, including cracking of Mifare encryption keys and performing targeted attacks against N...

uk: вхід без авторизації


uk: Комп'ютерні науки

description: The Cult of the Dead Cow changed the culture of the entire security industry, the attitude of companies who had ignored risks, and even how the feds dealt wi...

uk: вхід без авторизації

name: Cult of the Dead Cow - Change the World, cDc Style


uk: Комп'ютерні науки

description: Bluetooth Low energy version 5 has been published in late 2016, but we still have no sniffer supporting this specific version (and not that much compatible d...

uk: вхід без авторизації

name: Defeating Bluetooth Low Energy 5 PRNG for Fun and Jamming


uk: Комп'ютерні науки

description: In theory, brute force key recovery attacks against modern ciphers like AES should be impractical with the current state of computer hardware. It's often sai...

uk: вхід без авторизації

name: Key Search Attacks Against Modern Symmetric Ciphers


uk: Комп'ютерні науки

description: The security of common enterprise infrastructure devices such as desktops and laptops has advanced over the years through incremental improvements in operati...

uk: вхід без авторизації

name: Why You Should Fear Your mundane Office Equipment


uk: Комп'ютерні науки

description: EDR solutions have landed in Linux. With the ever increasing footprint of Linux machines deployed in data centers, offensive operators have to answer the cal...

uk: вхід без авторизації

name: Zombie Ant Farm Practical Tips for Playing Hide and Seek


uk: Комп'ютерні науки

description: After having compromised on-premise for many years, there is now also the cloud! Now your configuration mistakes can be accessed by anyone on the internet, w...

uk: вхід без авторизації

name: Im In Your Cloud Pwning Your Azure Environment


uk: Комп'ютерні науки

description: Like most modern devices, building controllers have increasingly become network connected, exposing them to a wider range of threats. If malicious actors cou...

uk: вхід без авторизації

name: HVACking Understand the Delta Between Security and Reality


uk: Комп'ютерні науки

description: Return-oriented Programming (ROP) has been the predominate code-reuse attack for over a decade, but there are other options. Many mitigations can detect ROP ...

uk: вхід без авторизації

name: JOP ROCKET A Wicked Tool for JOP Gadget Discovery


Go NULL Yourself

uk: Комп'ютерні науки

description: Input sanitization issues will always exist, although it’s surprising at how we’re still seeing amateur mistakes being made on everyday applications and syst...

uk: вхід без авторизації


uk: Комп'ютерні науки

description: This talk explores how AI is revolutionizing hardware side-channel attacks and what this new wave of attacks mean for the future of hardware cryptography. Ba...

uk: вхід без авторизації

name: Deep Learning Revolutionizing Side Channel Cryptanalysis - DEF CON 27 Conference


uk: Комп'ютерні науки

description: Your browser thinks my 192.168.1.1 is the same as your 192.168.1.1. Using a novel combination of redirects, Karma, JavaScript and caching we demonstrate that...

uk: вхід без авторизації

name: MI CASA SU CASA My 19216811 is Your 19216811 -


uk: Комп'ютерні науки

description: t's a nice sunny day on your vacation, the views are stunning, and like on any other day you take out your DSLR camera and start taking pictures. Sounds magi...

uk: вхід без авторизації

name: Say Cheese How I Ransomwared Your DSLR Camera - DEF CON 27 Conference


uk: Комп'ютерні науки

description: Buying Supreme is even harder when most of your competitors are AI. The era of bot purchasing has arrived and more often than not, purchasing shoes, shirts, ...

uk: вхід без авторизації

name: Rise of the Hypebots Scripting Streetwear


uk: Комп'ютерні науки

description: “5G is coming” (apparently). That probably means, over the next few years, more and more people are going to be using more and more cellular-connected device...

uk: вхід без авторизації

name: Reverse Engineering 4g Hotspots for Fun Bugs Net Financial Loss


uk: Комп'ютерні науки

description: Do you want to know how you can exploit DNS rebinding 10x faster, bypass prevention mechanisms, interactively browse the victim's internal network, and autom...

uk: вхід без авторизації

name: State of DNS Rebinding Attacks & Singularity of Origin


uk: Комп'ютерні науки

description: Reverse engineering is critical to exploitation. However, going through the process of reverse engineering can often lead to a great deal more than just unco...

uk: вхід без авторизації

name: Breaking the Back End Sometimes it's Just Bad Design


The ABC of Next Gen Shellcoding

uk: Комп'ютерні науки

description: Shellcodes are short executable stubs that are used in various attack scenarios, whenever code execution is possible. After briefly recalling how they work i...

uk: вхід без авторизації


Malproxy Leave Your Malware at Home

uk: Комп'ютерні науки

description: During a classic cyber attack, one of the major offensive goals is to execute code remotely on valuable machines. The purpose of that code varies on the spectrum from information extraction to physical damage. As defenders, our goal is to detect and eliminate any malicious code activity, while hackers continuously find ways to bypass the most advanced detection mechanisms. It’s an endless cat-and-mouse game where new mitigations and features are continuously added to the endpoint protection solutions and even the OS itself in order to protect the users against newly discovered attack techniques. In this talk, we present a new approach for malicious code to bypass most of endpoint protection measures. Our approach covertly proxies the malicious code operations over the network, never deploying the actual malicious code on the victim side. We are going to execute code on an endpoint, without really storing the code on disk or loading it to memory. This technique potentially allows attackers to run malicious code on remote victims, in such a way that the code is undetected by the victim’s security solutions. We denote this technique as “malproxying”. Hila Cohen Hila Cohen is a passionate Security Researcher at XM Cyber, where she investigates new attack techniques and develops detection and mitigation capabilities. Hila has a vast knowledge in the fields of malware analysis, reverse engineering and incident response. Amit Waisel Amit Waisel is a Senior Technical Leader at XM Cyber. He is a seasoned data security expert with vast experience in cyber offensive projects. Prior to XM Cyber, Amit filled multiple data security positions in the Israeli intelligence community. Amit is well experienced with malware detection and analysis techniques, operating system internals and security-oriented software development. He graduated with honors from Tel Aviv University with a MSc. in Computer Science.

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uk: Комп'ютерні науки

description: When it comes to process injection in Windows, there are only 6-7 fundamental techniques, right? Wrong. In this talk, we provide the most comprehensive to-date “Windows process injection” collection of techniques. We focus on Windows 10 x64, and on injections from running 64-bit medium integrity process to another running 64-bit medium integrity process, without privilege elevation. We pay special attention to the new Windows protection technologies, e.g. CFG and CIG. We differentiate between memory write primitives and execution techniques, and discuss memory allocation strategies. Our collection is curated, analyzed, tabulated, with straight-forward, research-grade PoCs. We tested each technique against Windows 10 x64 with and without protections, and we report on the requirements, limitations, and quirks of each technique. And of course – no decent DEF CON presentation is complete without new attacks. We describe a new memory writing primitive which is CFG-agnostic. We describe a new “stack bombing” execution method (based on the memory write primitive above) that is inherently safe (even though overwriting the stack is a-priori a dangerous and destabilizing action). Finally, we release a library of all write primitives and execution methods, so users can generate “tailor-made” process injections. Itzik Kotler Itzik Kotler is CTO and Co-Founder of SafeBreach. Itzik has more than a decade of experience researching and working in the computer security space. He is a recognized industry speaker, having spoken at DEF CON, Black Hat USA, Hack In The Box, RSA, CCC and H2HC. Prior to founding SafeBreach, Itzik served as CTO at Security-Art, an information security consulting firm, and before that he was SOC Team Leader at Radware. (NASDQ: RDWR). Amit Klein Amit Klein is a world renowned information security expert, with 28 years in information security and over 30 published technical and academic papers on this topic. Amit is the VP Security Research at SafeBreach, responsible for researching various infiltration, exfiltration and lateral movement attacks. Before SafeBreach, Amit was the CTO for Trusteer (acquired by IBM) for 8.5 years. Prior to Trusteer, Amit was chief scientist for Cyota (acquired by RSA) for 2 years, and prior to that, director of Security and Research for Sanctum (acquired by Watchfire, now part of IBM security division) for 7 years. Amit has a B.Sc. from the Hebrew University in Mathematics and Physics (magna cum laude, Talpiot program), recognized by InfoWorld as a CTO of the year 2010 , and has presented at BlackHat USA, DEF CON, NDSS, OWASP Global (keynote), InfoCom, DSN, HITB, RSA, OWASP EU, CertConf, BlueHat, CyberTech, APWG and AusCERT (keynote).

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name: Process Injection Techniques Gotta Catch Them All


uk: Комп'ютерні науки

description: WebAssembly is the newest way to play video games in your web browser. Both Unity3d and Unreal Engine now support WebAssembly, meaning the amount of WebAssembly games available is growing rapidly. Unfortunately the WebAssembly specification is missing some features game hackers might otherwise rely on. In this talk I will demonstrate adapting a number of game hacking techniques to WebAssembly while dealing with the limitations of the specification. For reverse engineers, I will show how to build and inject your own "watchpoints" for debugging WebAssembly binaries and how to insert symbols into a stripped binary. For game hackers, I will show how to use binary instrumentation to implement some old-school game hacking tricks and show off some new ones. I will be releasing two tools: a binary instrumentation library built for modifying WebAssembly binaries in the browser, and a browser extension that implements common game hacking methods a la Cheat Engine. Jack Baker Jack Baker is a professional vulnerability researcher and amateur video game hacker. His primary areas of expertise include web application security, embedded reverse engineering, and Tony Hawk's Pro Skater 3.

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name: Hacking WebAssembly Games with Binary Instrumentation