Tootfinder

Ich mag den Claim.

Google lets advertisers serve targeted ads across Google TV's 125 free channels, and reports 20M US monthly active Google TV and Android TV OS devices in 2023 (Umar Shakir/The Verge)
https://www.theverge.com/2024/6/10/24175676/google-fast-ads…

Google is ready to fill free streaming TV channels with ads
Google TV network lets advertisers get spots within free FAST streaming content. Google Ad campaigns can extend to YouTube as well.

@… Guffawed a little when I saw this on the other site.

Google lets advertisers serve targeted ads across Google TV's 125 free channels, and reports 20M US monthly active Google TV and Android TV OS devices in 2023 (Umar Shakir/The Verge)
https://www.theverge.com/2024/6/10/24175676/google-fast-ads…

Google is ready to fill free streaming TV channels with ads
Google TV network lets advertisers get spots within free FAST streaming content. Google Ad campaigns can extend to YouTube as well.

heise Jobs IT Tag am 19. Juni in Köln
Am 19. Juni findet von 12 bis 17 Uhr im KOMED 6 im Mediapark - Köln der heise Jobs IT Tag statt. Jetzt kostenlos anmelden!
https://www.heise.de/news/hei…

Ratfish part 1 was pretty good but I don't know if the format give enough clues to make it a game that works. https://www.dropout.tv/game-changer/season:6/videos/ratfish-part-1

Ratfish (Part 1) - Season 6 - Dropout
Seven players choose to not be true to themselves, and to be someone else.

Trump refusal to send National Guard on Jan. 6 infuriated top Dem, new video shows
https://thehill.com/homenews/senate/4714732-new-video-shows-schumer-fury-over-trump-not-sending-national-guard-on-jan-6/

Trump finds new ways to praise and celebrate Jan. 6 rioters (Steve Benen/MSNBC)
https://www.msnbc.com/rachel-maddow-show/maddowblog/trump-finds-new-ways-praise-celebrate-jan-6-rioters-rcna156294
http://www.memeorandum.com/240610/p60#a240610p60

GM is investing another $850M into Cruise to help cover its operational costs as it slowly resumes testing its self-driving vehicles in some US cities (Andrew J. Hawkins/The Verge)
https://www.theverge.com/2024/6/11/24176206/gm-cru…

GM pumps $850 million in Cruise to keep struggling robotaxi company afloat
GM is investing $850 million into Cruise to help the struggling robotaxi company cover its operational costs. The company shut down operations after a pedestrian was struck by a driverless car.

🧮 Greece’s Economic Odyssey: Persistent Challenges and Pathways Forward
#economics

Greece’s Economic Odyssey: Persistent Challenges and Pathways Forward
Two years after the COVID-19 pandemic, the Greek economy seems to have overcome the turmoil of the pandemic crisis as well as that of the following energy crisis. Nevertheless, it would be wrong to assume that the Greek economy has returned to a sound state, since this was not really the case even before the pandemic. Furthermore, the anemic growth rates of the pre-pandemic period were followed by an equally weak average growth rate (including the impact of the pandemic), as some of the signifi…

Windows won’t take screenshots of everything you do after all — unless you opt in #windows #ai #recall :windows:

The longer you look at Elon Musk, the worse he looks. Kinda like the Cybertruck, really.
#elonmusk #cybertruck
“Elon Musk has unusual relationships with women at SpaceX, WSJ reports”

Elon Musk has unusual relationships with women at SpaceX, WSJ reports
The Wall Street Journal reports on multiple women who worked at SpaceX and what they told others about their relationships with Elon Musk.

„Жълтопаветен", както вика Бойко Борисов, избор и в моята секция (тоест комшиите ми). Това е 24 МИР, същият МИР като на Капитана @…
Интересни са разликите между машинния и хартиения вот, нали? Другото интересно за мен е, че от години съм поизгубил връзка с „комшиите“ от „квартала“ и не си знаем политическите предпочитания.

In a forthcoming book, "The New Landlord, Powered by Big Data, and Artificial Intelligence"
James Nelson reveals that real estate heir, Harlan Crow created rent-gouging corporation RealPage in 1998
Yeah, that Harlan Crow, the owner of at least one US Supreme Court Justice: Clarence Thomas

FBI raid on real estate company linked to Harlan Crow's RealPage rental price fixing
A tip of the hat to David Cay Johnston, who opened his interview on the Mark Thompson Show yesterday by noting a story that, so far as I can tell at this time, has been completely blacked out of the news mainstream media. Two weeks ago, on Wednesday,...

Fantasy Baseball SP Roundup: Loucrative Varland
#MLB #FantasyBaseball #PitcherList

On Stewart's Perturbation Theorem for SVD
Ren-Cang Li, Ninoslav Truhar, Lei-Hong Zhang
https://arxiv.org/abs/2406.06901 https://a…

On Stewart's Perturbation Theorem for SVD
This paper establishes a variant of Stewart's theorem (Theorem~6.4 of Stewart, {\em SIAM Rev.}, 15:727--764, 1973) for the singular subspaces associated with the SVD of a matrix subject to perturbations. Stewart's original version uses both the Frobenius and spectral norms, whereas the new variant uses the spectral norm and any unitarily invariant norm that offer choices per convenience of particular applications and lead to sharper bounds than that straightforwardly derived from Stewart's orig…

I will only say I remain very disappointed in VIU Admin's approach.
VIU PSE statement:
https://www.instagram.com/reel/C8DQMU5BgK2/?igsh=MXc1ZWt4NXkzb2g4bA==
VIU Admin letter:
"Dear VIU community,
Today, Vanco…

#Upcoming Originally released in 1986, “TGCD1” is a long collage of studio recordings by from 1976, foreshadowing the live #ThrobbingGristle experience. Available again on CD after 25 years, and vinyl for the very first time via

TGCD1, by Throbbing Gristle
1 track album

Third Degree Price Discrimination Under Costly Information Acquisition
Irfan Tekdir
https://arxiv.org/abs/2406.06026 https://arxiv.or…

Third Degree Price Discrimination Under Costly Information Acquisition
This paper investigates third-degree price discrimination under endogenous market segmentation. Segmenting a market requires access to information about consumers, and this information comes with a cost. I explore the trade-offs between the benefits of segmentation and the costs of information acquisition, revealing a non-monotonic relationship between consumer surplus and the cost of information acquisition for monopolist. I show that in some markets, allowing the monopolist easier access to c…

Operator-Valued Twisted Araki-Woods Algebras
Rahul Kumar R, Melchior Wirth
https://arxiv.org/abs/2406.06179 https://arxiv.org/pdf/240…

Operator-Valued Twisted Araki-Woods Algebras
We introduce operator-valued twisted Araki-Woods algebras. These are operator-valued versions of a class of second quantization algebras that includes $q$-Gaussian and $q$-Araki-Woods algebras and also generalize Shlyakhtenko's von Neumann algebras generated by operator-valued semicircular variables. We develop a disintegration theory that reduces the isomorphism type of operator-valued twisted Araki-Woods algebras over type I factors to the scalar-valued case. Moreover, these algebras come wit…

This https://arxiv.org/abs/2404.02856 has been replaced.
initial toot: https://mastoxiv.page/@arX…

An Information Bottleneck Approach for Markov Model Construction
Markov state models (MSMs) are valuable for studying dynamics of protein conformational changes via statistical analysis of molecular dynamics (MD) simulations. In MSMs, the complex configuration space is coarse-grained into conformational states, with the dynamics modeled by a series of Markovian transitions among these states at discrete lag times. Constructing the Markovian model at a specific lag time requires state defined without significant internal energy barriers, enabling internal dyn…

This https://arxiv.org/abs/2406.00827 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_eco…

LaLonde (1986) after Nearly Four Decades: Lessons Learned
In 1986, Robert LaLonde published an article that compared nonexperimental estimates to experimental benchmarks LaLonde (1986). He concluded that the nonexperimental methods at the time could not systematically replicate experimental benchmarks, casting doubt on the credibility of these methods. Following LaLonde's critical assessment, there have been significant methodological advances and practical changes, including (i) an emphasis on estimators based on unconfoundedness, (ii) a focus on the…

This https://arxiv.org/abs/2312.02203 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qbi…

Learning High-Order Relationships of Brain Regions
Discovering reliable and informative relationships among brain regions from functional magnetic resonance imaging (fMRI) signals is essential in phenotypic predictions. Most of the current methods fail to accurately characterize those interactions because they only focus on pairwise connections and overlook the high-order relationships of brain regions. We propose that these high-order relationships should be maximally informative and minimally redundant (MIMR). However, identifying such high-o…

Smiles2Dock: an open large-scale multi-task dataset for ML-based molecular docking
Thomas Le Menestrel, Manuel Rivas
https://arxiv.org/abs/2406.05738 https…

Smiles2Dock: an open large-scale multi-task dataset for ML-based molecular docking
Docking is a crucial component in drug discovery aimed at predicting the binding conformation and affinity between small molecules and target proteins. ML-based docking has recently emerged as a prominent approach, outpacing traditional methods like DOCK and AutoDock Vina in handling the growing scale and complexity of molecular libraries. However, the availability of comprehensive and user-friendly datasets for training and benchmarking ML-based docking algorithms remains limited. We introduce…

A Dutch court convicts and sentences six men in connection with the murder of celebrity crime reporter Peter R. De Vries on an Amsterdam street in July 2021 (Seb Starcevic/Politico)
https://www.politico.eu/article/peter-r-de

Court convicts 6 over Dutch crime reporter’s murder
Killers ambushed and shot Peter R. de Vries with “staggering” ease.

Trump refusal to send National Guard on Jan. 6 infuriated top Dem, new video shows
https://thehill.com/homenews/senate/4714732-new-video-shows-schumer-fury-over-trump-not-sending-national-guard-on-jan-6/

Waymo issues a software update to its 672 vehicles after one collided with a telephone pole in Phoenix on May 21, marking Waymo's second recall ever (Andrew J. Hawkins/The Verge)
https://www.theverge.com/2024/6/12/24175489/way…

Waymo issues software and mapping recall after robotaxi crashes into a telephone pole
Waymo is recalling its driverless vehicle software after one of its robotaxis crashed into a telephone poll in Phoenix. It’s the Google spinoff’s second-ever recall.

I really enjoy the realism and expectation management on Wikivoyage: “It's not scenic, but has a rich industrial heritage. (…) Other Polish cities have prettified themselves into romantic budget-flight weekend destinations - that was never realistic for Katowice.“

Discord music bot Rythm relaunches three years after YouTube forced it offline, with a $4.99/month paid tier and plans to launch a mobile app later this year (Tom Warren/The Verge)
https://www.theverge.com/2024/6/11/24175920/discord-ryt…

Discord’s Rythm music bot returns with a mission to overhaul shared listening
The Discord Rythm music bot is back. After Google forced the bot offline three years ago, Rythm has been working on a new experience that’s launching today.

This https://arxiv.org/abs/2405.10410 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

The fast committor machine: Interpretable prediction with kernels
In the study of stochastic systems, the committor function describes the probability that a system starting from an initial configuration $x$ will reach a set $B$ before a set $A$. This paper introduces an efficient and interpretable algorithm for approximating the committor, called the "fast committor machine" (FCM). The FCM uses simulated trajectory data to build a kernel-based model of the committor. The kernel function is constructed to emphasize low-dimensional subspaces which optimally de…

[2024-06-11 Tue (UTC), 3 new articles found for econ.TH Theoretical Economics]

Absolute dilations of ucp self-adjoint Fourier multipliers: the non unimodular case
Charles Duquet, Christian Le Merdy
https://arxiv.org/abs/2406.06074 htt…

Absolute dilations of ucp self-adjoint Fourier multipliers: the non unimodular case
Let $φ$ be a normal semi-finite faithful weight on a von Neumann algebra $A$,let $(σ^φ_r)_{r\in{\mathbb R}}$ denote the modular automorphism group of $φ$, and let $T\colon A\to A$ be a linear map. We say that $T$ admits an absolute dilation if there exist another von Neumann algebra $M$ equipped with a normal semi-finite faithful weight $ψ$, a $w^*$-continuous, unital and weight-preserving $*$-homomorphism $J\colon A\to M$ such that $σ^ψ\circ J=J\circ σ^φ$, as well as a weight-preservi…

This https://arxiv.org/abs/2403.11389 has been replaced.
initial toot: https://mastoxiv.page/@arX…

A biosensor based on magnetoelastic waves for detection of antibodies in human plasma for COVID-19 serodiagnosis
The study proposes a new efficient wireless biosensor based on magnetoelastic waves for the detection of antibodies in human plasma, aiming at the serological diagnosis of COVID-19. The biosensor was functionalized with the N antigen - nucleocapsid phosphoprotein of the SARS-CoV-2 virus. Validation analyses, by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting, atomic force microscopy (AFM), scanning electron microscopy (SEM), micro-Raman spectroscopy, confi…

Data-Driven Real-time Coupon Allocation in the Online Platform
Jinglong Dai, Hanwei Li, Weiming Zhu, Jianfeng Lin, Binqiang Huang
https://arxiv.org/abs/2406.05987

Data-Driven Real-time Coupon Allocation in the Online Platform
Traditionally, firms have offered coupons to customer groups at predetermined discount rates. However, advancements in machine learning and the availability of abundant customer data now enable platforms to provide real-time customized coupons to individuals. In this study, we partner with Meituan, a leading shopping platform, to develop a real-time, end-to-end coupon allocation system that is fast and effective in stimulating demand while adhering to marketing budgets when faced with uncertain…

This https://arxiv.org/abs/2312.02203 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qbi…

Learning High-Order Relationships of Brain Regions
Discovering reliable and informative relationships among brain regions from functional magnetic resonance imaging (fMRI) signals is essential in phenotypic predictions. Most of the current methods fail to accurately characterize those interactions because they only focus on pairwise connections and overlook the high-order relationships of brain regions. We propose that these high-order relationships should be maximally informative and minimally redundant (MIMR). However, identifying such high-o…

Ich wäre dann wieder bereit für Sommerwetter.

#NowPlaying I’m on a mission to have this #Unrest EP on repeat times infinity. https://www.you…

Eher pessimistische Aussichten.
https://mastodon.xyz/@johl/112591507564153368

This https://arxiv.org/abs/2405.09424 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

On backward problem for a time-fractional fourth order parabolic equation
This paper is concerned with the inverse problem of retrieving the initial value of a time-fractional fourth order parabolic equation from source and final time observation. The considered problem is an {\it ill-posed problem.} We obtain regularized approximations for the sought initial value by employing the quasi-boundary value method, its modified version and by Fourier truncation method(FTM). We provide both the apriori and aposteriori parameter choice strategies and derive the error estima…

Dilation distance and the stability of ergodic commutation relations
Malte Gerhold, Orr Shalit
https://arxiv.org/abs/2406.05864 https://

Dilation distance and the stability of ergodic commutation relations
We revisit and generalize the notion of dilation distance ${\rm d_{D}}(u,v)$ between unitary tuples and study its relation to the natural Haagerup-Rørdam distance ${\rm d_{HR}}(u,v) = \inf\{\|π(u) - ρ(v)\|\}$, where the infimum is taken over all pairs of faithful representations $π\colon C^*(u) \to B(\mathcal{H})$, $ρ\colon C^*(v) \to B(\mathcal{H})$. We show that ${\rm d_{HR}}(u,v)\leq 10\operatorname{d_{rD}}(u,v)^{1/2}$, where ${\rm d_{rD}}(u,v)$ is a relaxed dilation distance,…

A story of cooperation: Centrosome-cytoskeleton interactions and implications
Subarna Dutta, Arnab Barua
https://arxiv.org/abs/2406.06135 https://

A story of cooperation: Centrosome-cytoskeleton interactions and implications
A structural link between cell's centrosome and cytoskeleton has been proposed years ago. Centrosomes are usually located in the proximity to the nuclei and maintain nucleus-centrosome axis. This positioning aids in determining the polarity of interphase cells and ensure spindle assembly in mitotic cells. Centrosome also maintains physical interaction with different forms of cytoskeleton to trade-off between internal architecture and cell polarity in tissue specific as well as development speci…

This https://arxiv.org/abs/2403.01585 has been replaced.
link: https://scholar.google.com/scholar?q=a

Calibrating doubly-robust estimators with unbalanced treatment assignment
Machine learning methods, particularly the double machine learning (DML) estimator (Chernozhukov et al., 2018), are increasingly popular for the estimation of the average treatment effect (ATE). However, datasets often exhibit unbalanced treatment assignments where only a few observations are treated, leading to unstable propensity score estimations. We propose a simple extension of the DML estimator which undersamples data for propensity score modeling and calibrates scores to match the origin…

#NowPlaying Taking a quick break to check out this new #YellowSwans tape. It’s the first of several documenting their most recent recordings based on some frameworks they gave themselves for playing live recently.

This https://arxiv.org/abs/2405.03016 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Pathwise uniform convergence of a full discretization for a three-dimensional stochastic Allen-Cahn equation with multiplicative noise
This paper analyzes a full discretization of a three-dimensional stochastic Allen-Cahn equation with multiplicative noise. The discretization uses the Euler scheme for temporal discretization and the finite element method for spatial discretization. A key contribution of this work is the introduction of a novel stability estimate for a discrete stochastic convolution, which plays a crucial role in establishing pathwise uniform convergence estimates for fully discrete approximations of nonlinear…

On a question of Blecher, Pisier, Shlyakhtenko
Roy Araiza, Marius Junge, Carlos Palazuelos
https://arxiv.org/abs/2406.05302 https://a…

On a question of Blecher, Pisier, Shlyakhtenko
We show the failure of a matricial version of Grothendieck's theorem for operator spaces, thereby resolving a long-standing open question in the field. Moreover, by showing that such a counterexample can occur in the simplest context of commutative $C^*$-algebras, we address some other open questions in operator algebras. Our constructions, completely explicit and fairly simple, are inspired by some techniques in quantum information theory.

Nanoparticle uptake by a semi-permeable, spherical cell from an external planar diffusive field. II. Numerical study of temporal and spatial development validated using FEM
Sandeep Santhosh Kumar, Stanley J. Miklavcic
https://arxiv.org/abs/2406.06013

Nanoparticle uptake by a semi-permeable, spherical cell from an external planar diffusive field. II. Numerical study of temporal and spatial development validated using FEM
In this paper we present a mathematical study of particle diffusion inside and outside a spherical biological cell that has been exposed on one side to a propagating planar diffusive front. The media inside and outside the spherical cell are differentiated by their respective diffusion constants. A closed form, large-time, asymptotic solution is derived by the combined means of Laplace transform, separation of variables and asymptotic series development. The solution process is assisted by mean…

This https://arxiv.org/abs/2303.00982 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_eco…

Aggregated Intersection Bounds and Aggregated Minimax Values
This paper proposes a novel framework of aggregated intersection bounds, where the target parameter is obtained by averaging the minimum (or maximum) of a collection of regression functions over the covariate space. Examples of such quantities include the lower and upper bounds on distributional effects (Fréchet-Hoeffding, Makarov) as well as the optimal welfare in statistical treatment choice problems. The proposed estimator -- the envelope score estimator -- is shown to have an oracle proper…

Great 🧵 about Apple’s Private Cloud Compute system to handle tasks beyond what can be done on device. I have mixed feelings about so-called “artificial intelligence”. I don’t like how data gets scraped without permission, and is displacing jobs. But, when it comes to using large language models as a tool, like better organizing my inbox, I’m okay with that. Obviously, when the rubber meets the road, I’m likely to change my mind.

This https://arxiv.org/abs/2404.18003 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Estimation of uncertainties in the density driven flow in fractured porous media using MLMC
We use the Multi Level Monte Carlo method to estimate uncertainties in a Henry-like salt water intrusion problem with a fracture. The flow is induced by the variation of the density of the fluid phase, which depends on the mass fraction of salt. We assume that the fracture has a known fixed location but an uncertain aperture. Other input uncertainties are the porosity and permeability fields and the recharge. In our setting, porosity and permeability vary spatially and recharge is time-dependen…

[2024-06-11 Tue (UTC), 4 new articles found for math.OA Operator Algebras]

Analysis of non-equilibrium fluctuations in a number of COVID-19 cases and deaths based on time-convolutionless projection-operator method
Michio Tokuyama
https://arxiv.org/abs/2406.05611

Analysis of non-equilibrium fluctuations in a number of COVID-19 cases and deaths based on time-convolutionless projection-operator method
The non-equilibrium fluctuations observed in a number of COVID-19 cases and deaths are analyzed from a statistical-dynamical point view. By investigating the data observed around the world which were collected from January 15, 2020 to April 28, 2023 at https://coronavirus.jhu.edu/, we first show that the dynamics of the fluctuations is described by a stochastic equation whose stochastic force is a multiplicative type. By employing the time-convolutionless projection-operator method in open syst…

Robustness to Missing Data: Breakdown Point Analysis
Daniel Ober-Reynolds
https://arxiv.org/abs/2406.06804 https://arxiv.org/pdf/2406…

Robustness to Missing Data: Breakdown Point Analysis
Missing data is pervasive in econometric applications, and rarely is it plausible that the data are missing (completely) at random. This paper proposes a methodology for studying the robustness of results drawn from incomplete datasets. Selection is measured as the squared Hellinger divergence between the distributions of complete and incomplete observations, which has a natural interpretation. The breakdown point is defined as the minimal amount of selection needed to overturn a given result. …

This https://arxiv.org/abs/2404.03603 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

A semi-implicit second-order temporal scheme for solving the pressure head-based form of Richards' and advection-dispersion equations
In this study, a novel semi-implicit second-order temporal scheme combined with the finite element method for space discretization is proposed to solve the coupled system of infiltration and solute transport in unsaturated porous media. The Richards equation is used to describe unsaturated flow, while the advection-dispersion equation (ADE) is used for modeling solute transport. The proposed approach is used to linearize the system of equations in time, eliminating the need of iterative process…

Nanoparticle uptake by a semi-permeable, spherical cell from an external planar diffusive field. I. Mathematical model and asymptotic solution
Stanley J. Miklavcic
https://arxiv.org/abs/2406.05353

Nanoparticle uptake by a semi-permeable, spherical cell from an external planar diffusive field. I. Mathematical model and asymptotic solution
In this paper we consider the diffusion of nanoparticles taken up by a semi-permeable spherical cell placed in the path of a diffusive particle field generated by an external planar source. The cell interior and exterior are characterized by different diffusive properties, while the cell is able to accommodate a different saturation level of particles at steady state than is present in the external medium. The situation models the practical problem of biological cells exposed from one direction…

[2024-06-12 Wed (UTC), 2 new articles found for econ.EM Econometrics]

Heat operators and isometry groups of Cuntz-Krieger algebras
Dimitris Michail Gerontogiannis, Magnus Goffeng, Bram Mesland
https://arxiv.org/abs/2406.07416

Heat operators and isometry groups of Cuntz-Krieger algebras
This paper introduces heat semigroups of topological Markov chains and Cuntz-Krieger algebras by means of spectral noncommutative geometry. Using recent advances on the logarithmic Dirichlet Laplacian on Ahlfors regular metric-measure spaces, we construct spectral triples on Cuntz-Krieger algebras from singular integral operators. These spectral triples exhaust K-homology and for Cuntz algebras we can compute their heat operators explicitly as Riesz potential operators. We also describe their i…

This https://arxiv.org/abs/2403.00682 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

An iterative method for the solution of Laplace-like equations in high and very high space dimensions
This paper deals with the equation $-Δu+μu=f$ on high-dimensional spaces $\mathbb{R}^m$, where the right-hand side $f(x)=F(Tx)$ is composed of a separable function $F$ with an integrable Fourier transform on a space of a dimension $n>m$ and a linear mapping given by a matrix $T$ of full rank and $μ\geq 0$ is a constant. For example, the right-hand side can explicitly depend on differences $x_i-x_j$ of components of $x$. We show that the solution of this equation can be expanded into sums of …

[2024-06-11 Tue (UTC), 4 new articles found for physics.bio-ph Biological Physics]

Bijections Between Sets of Invariant Ideals, Via the Ladder Technique
Matthew Gillespie, S. Kaliszewski, John Quigg, Dana P. Williams
https://arxiv.org/abs/2406.06780

Bijections Between Sets of Invariant Ideals, Via the Ladder Technique
We present a new method of establishing a bijective correspondence - in fact, a lattice isomorphism - between action- and coaction-invariant ideals of C*-algebras and their crossed products by a fixed locally compact group. It is known that such a correspondence exists whenever the group is amenable; our results hold for any locally compact group under a natural form of coaction invariance.

Causal Interpretation of Regressions With Ranks
Lihua Lei
https://arxiv.org/abs/2406.05548 https://arxiv.org/pdf/2406.05548

Causal Interpretation of Regressions With Ranks
In studies of educational production functions or intergenerational mobility, it is common to transform the key variables into percentile ranks. Yet, it remains unclear what the regression coefficient estimates with ranks of the outcome or the treatment. In this paper, we derive effective causal estimands for a broad class of commonly-used regression methods, including the ordinary least squares (OLS), two-stage least squares (2SLS), difference-in-differences (DiD), and regression discontinuity…

This https://arxiv.org/abs/2402.18721 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Collocation methods for nonlinear differential equations on low-rank manifolds
We introduce new methods for integrating nonlinear differential equations on low-rank manifolds. The methods are based on oblique projectors onto the tangent spaces of low-rank manifolds with an interpolation property that collocates the differential equation on the manifold. These projections yield evolution equations that enable low-rank time integration of any vectorfield that can be evaluated entry-wise. The proposed methods do not require the vectorfield to have a low-rank structure, thus …

This https://arxiv.org/abs/2402.16747 has been replaced.
initial toot: https://mastoxiv.page/@arX…

Recent progress in the physical principles of dynamic ground self-righting
Animals and robots must self-right on the ground after overturning. Biology research described various strategies and motor patterns in many species. Robotics research devised many strategies. However, we do not well understand how the physical principles of how the need to generate mechanical energy to overcome the potential energy barrier governs behavioral strategies and 3-D body rotations given the morphology. Here I review progress on this which I led studying cockroaches self-righting on …

[2024-06-12 Wed (UTC), 3 new articles found for math.OA Operator Algebras]

Cluster GARCH
Chen Tong, Peter Reinhard Hansen, Ilya Archakov
https://arxiv.org/abs/2406.06860 https://arxiv.org/pdf/2406.06860

Cluster GARCH
We introduce a novel multivariate GARCH model with flexible convolution-t distributions that is applicable in high-dimensional systems. The model is called Cluster GARCH because it can accommodate cluster structures in the conditional correlation matrix and in the tail dependencies. The expressions for the log-likelihood function and its derivatives are tractable, and the latter facilitate a score-drive model for the dynamic correlation structure. We apply the Cluster GARCH model to daily retur…

This https://arxiv.org/abs/2402.09803 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

An Inverse Problems Approach to Pulse Wave Analysis in the Human Brain
Cardiac pulsations in the human brain have received recent interest due to their possible role in the pathogenesis of neurodegenerative diseases. Further interest stems from their possible application as an endogenous signal source that can be utilized for brain imaging in general. The (pulse-)wave describing the blood flow velocity along an intracranial artery consists of a forward (anterograde) and a backward (retrograde, reflected) part, but measurements of this wave usually consist of a sup…

Photosynthetic energy transfer: missing in action (detected spectroscopy)?
Ariba Javed, Julian L\"uttig, Kate\v{r}ina Charv\'atov\'a, Stephanie E. Sanders, Rhiannon Willow, Muyi Zhang, Alastair T. Gardiner, Pavel Mal\'y, Jennifer P. Ogilvie
https://arxiv.org/abs/2406.06784…

Photosynthetic energy transfer: missing in action (detected spectroscopy)?
In recent years, action-detected ultrafast spectroscopies have gained popularity. These approaches offer some advantages over their coherently-detected counterparts, enabling spatially-resolved and operando measurements with high sensitivity. However, there are also fundamental limitations connected to the different process of signal generation in action-detected experiments. Specifically, state mixing by nonlinear interactions during signal emission leads to a large static background which can…

[2024-06-11 Tue (UTC), 2 new articles found for econ.EM Econometrics]

This https://arxiv.org/abs/2402.02902 has been replaced.
link: https://scholar.google.com/scholar?q=a

The eXtended Virtual Element Method for elliptic problems with weakly singular solutions
This paper introduces a novel eXtended virtual element method, an extension of the conforming virtual element method. The XVEM is formulated by incorporating appropriate enrichment functions in the local spaces. The method is designed to handle highly generic enrichment functions, including singularities arising from fractured domains. By achieving consistency on the enrichment space, the method is proven to achieve arbitrary approximation orders even in the presence of singular solutions. The …

[2024-06-12 Wed (UTC), 1 new article found for physics.bio-ph Biological Physics]

This https://arxiv.org/abs/2401.08814 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Inviscid Burgers as a degenerate elliptic problem
We demonstrate the feasibility of a scheme to obtain approximate weak solutions to the (inviscid) Burgers equation in conservation and Hamilton-Jacobi form, treated as degenerate elliptic problems. We show different variants recover non-unique weak solutions as appropriate, and also specific constructive approaches to recover the corresponding entropy solutions.

This https://arxiv.org/abs/2312.13625 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

New Convergence Analysis of GMRES with Weighted Norms, Preconditioning and Deflation, Leading to a New Deflation Space
New convergence bounds are presented for weighted, preconditioned, and deflated GMRES for the solution of large, sparse, non-Hermitian linear systems. These bounds are given for the case when the Hermitian part of the coefficient matrix is positive definite, the preconditioner is Hermitian positive definite, and the weight is equal to the preconditioner. The new bounds are a novel contribution in and of themselves. In addition, they are sufficiently explicit to indicate how to choose the precon…

This https://arxiv.org/abs/2311.16167 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Moving Sampling Physics-informed Neural Networks induced by Moving Mesh PDE
In this work, we propose an end-to-end adaptive sampling neural network (MMPDE-Net) based on the moving mesh method, which can adaptively generate new sampling points by solving the moving mesh PDE. This model focuses on improving the quality of sampling points generation. Moreover, we develop an iterative algorithm based on MMPDE-Net, which makes the sampling points more precise and controllable. Since MMPDE-Net is a framework independent of the deep learning solver, we combine it with physics…

This https://arxiv.org/abs/2309.04889 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

A subspace constrained randomized Kaczmarz method for structure or external knowledge exploitation
We study a version of the randomized Kaczmarz algorithm for solving systems of linear equations where the iterates are confined to the solution space of a selected subsystem. We show that the subspace constraint leads to an accelerated convergence rate, especially when the system has approximately low-rank structure. On Gaussian-like random data, we show that it results in a form of dimension reduction that effectively increases the aspect ratio of the system. Furthermore, this method serves as…

This https://arxiv.org/abs/2309.02289 has been replaced.
link: https://scholar.google.com/scholar?q=a

An operator preconditioned combined field integral equation for electromagnetic scattering
This paper aims to address two issues of integral equations for the scattering of time-harmonic electromagnetic waves by a perfect electric conductor with Lipschitz continuous boundary: ill-conditioned {boundary element Galerkin matrices} on fine meshes and instability at spurious resonant frequencies. The remedy to ill-conditioned matrices is operator preconditioning, and resonant instability is eliminated by means of a combined field integral equation. Exterior traces of single and double lay…

This https://arxiv.org/abs/2305.03469 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Data-inspired modeling of accidents in traffic flow networks
We consider hyperbolic partial differential equations (PDEs) for a dynamic description of the traffic behavior in road networks. These equations are coupled to a Hawkes process that models traffic accidents taking into account their self-excitation property which means that accidents are more likely in areas in which another accident just occurred. We discuss how both model components interact and influence each other. A data analysis reveals the self-excitation property of accidents and determ…

This https://arxiv.org/abs/2403.12826 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Cross Interpolation for Solving High-Dimensional Dynamical Systems on Low-Rank Tucker and Tensor Train Manifolds
We present a novel tensor interpolation algorithm for the time integration of nonlinear tensor differential equations (TDEs) on the tensor train and Tucker tensor low-rank manifolds, which are the building blocks of many tensor network decompositions. This paper builds upon our previous work (Donello et al., Proceedings of the Royal Society A, Vol. 479, 2023) on solving nonlinear matrix differential equations on low-rank matrix manifolds using CUR decompositions. The methodology we present offe…

This https://arxiv.org/abs/2403.03905 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Black-Box $k$-to-$1$-PCA Reductions: Theory and Applications
The $k$-principal component analysis ($k$-PCA) problem is a fundamental algorithmic primitive that is widely-used in data analysis and dimensionality reduction applications. In statistical settings, the goal of $k$-PCA is to identify a top eigenspace of the covariance matrix of a distribution, which we only have black-box access to via samples. Motivated by these settings, we analyze black-box deflation methods as a framework for designing $k$-PCA algorithms, where we model access to the unknow…

This https://arxiv.org/abs/2402.06429 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Exact a posteriori error control for variational problems via convex duality and explicit flux reconstruction
A posteriori error estimates are an important tool to bound discretization errors in terms of computable quantities avoiding regularity conditions that are often difficult to establish. For non-linear and non-differentiable problems, problems involving jumping coefficients, and finite element methods using anisotropic triangulations, such estimates often involve large factors, leading to sub-optimal error estimates. By making use of convex duality arguments, exact and explicit error representat…

This https://arxiv.org/abs/2401.11890 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Shape uncertainty quantification of Maxwell eigenvalues and -modes with application to TESLA cavities
We consider Maxwell eigenvalue problems on uncertain shapes with perfectly conducting TESLA cavities being the driving example. Due to the shape uncertainty the resulting eigenvalues and eigenmodes are also uncertain and it is well known that the eigenvalues may exhibit crossings or bifurcations under perturbation. We discuss how the shape uncertainties can be modelled using the domain mapping approach and how the deformation mapping can be expressed as coefficients in Maxwell's equations. Usin…

This https://arxiv.org/abs/2401.07806 has been replaced.
link: https://scholar.google.com/scholar?q=a

Optimal design for linear models via gradient flow
Optimal experimental design (OED) aims to choose the observations in an experiment to be as informative as possible, according to certain statistical criteria. In the linear case (when the observations depend linearly on the unknown parameters), it seeks the optimal weights over rows of the design matrix A under certain criteria. Classical OED assumes a discrete design space and thus a design matrix with finite dimensions. In many practical situations, however, the design space is continuous-va…

This https://arxiv.org/abs/2311.16019 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Sketched and Truncated Polynomial Krylov Subspace Methods: Matrix Sylvester Equations
Thanks to its great potential in reducing both computational cost and memory requirements, combining sketching and Krylov subspace techniques has attracted a lot of attention in the recent literature on projection methods for linear systems, matrix function approximations, and eigenvalue problems. Applying this appealing strategy in the context of linear matrix equations turns out to be far more involved than a straightforward generalization. These difficulties include analyzing well-posedness …

This https://arxiv.org/abs/2311.15738 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

On full linear convergence and optimal complexity of adaptive FEM with inexact solver
The ultimate goal of any numerical scheme for partial differential equations (PDEs) is to compute an approximation of user-prescribed accuracy at quasi-minimal computational time. To this end, algorithmically, the standard adaptive finite element method (AFEM) integrates an inexact solver and nested iterations with discerning stopping criteria balancing the different error components. The analysis ensuring optimal convergence order of AFEM with respect to the overall computational cost critical…

This https://arxiv.org/abs/2309.09036 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

A posteriori error control for a Discontinuous Galerkin approximation of a Keller-Segel model
We provide a posteriori error estimates for a discontinuous Galerkin scheme for the parabolic-elliptic Keller-Segel system in 2 or 3 space dimensions. The estimates are conditional, in the sense that an a posteriori computable quantity needs to be small enough - which can be ensured by mesh refinement - and optimal in the sense that the error estimator decays with the same order as the error under mesh refinement. A specific feature of our error estimator is that it can be used to prove existen…

This https://arxiv.org/abs/2304.09676 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Efficient computation of the sinc matrix function for the integration of second-order differential equations
This work deals with the numerical solution of systems of oscillatory second-order differential equations which often arise from the semi-discretization in space of partial differential equations. Since these differential equations exhibit (pronounced or highly) oscillatory behavior, standard numerical methods are known to perform poorly. Our approach consists in directly discretizing the problem by means of Gautschi-type integrators based on $\operatorname{sinc}$ matrix functions. The novelty …

This https://arxiv.org/abs/2303.02339 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

A Nyström Method for Scattering by a Two-layered Medium with a Rough Boundary
This paper considers the problems of scattering of time-harmonic acoustic waves by a two-layered medium with a non-locally perturbed boundary (called a rough boundary in this paper) in two dimensions, where a Dirichlet or impedance boundary condition is imposed on the boundary. The two-layered medium is composed of two unbounded media with different physical properties and the interface between the two media is considered to be a planar surface. We formulate the considered scattering problems a…

This https://arxiv.org/abs/2210.08247 has been replaced.
link: https://scholar.google.com/scholar?q=a

A sparse spectral method for fractional differential equations in one-spatial dimension
We develop a sparse spectral method for a class of fractional differential equations, posed on $\mathbb{R}$, in one dimension. These equations can include sqrt-Laplacian, Hilbert, derivative and identity terms. The numerical method utilizes a basis consisting of weighted Chebyshev polynomials of the second kind in conjunction with their Hilbert transforms. The former functions are supported on $[-1,1]$ whereas the latter have global support. The global approximation space can contain different …

Minimal-norm solution to the Fredholm integral equations of the first kind via the H-HK formulation
Renjun Qiu, Ming Xu, Wei Qu
https://arxiv.org/abs/2406.07303

Minimal-norm solution to the Fredholm integral equations of the first kind via the H-HK formulation
The Fredholm integral equations of the first kind is a typical ill-posed problem, so that it is usually difficult to obtain its analytical minimal-norm solution. This paper gives a closed-form minimal-norm solution for the degenerate kernel equations based on the H-HK formulation. Furthermore, it has been shown that the structure of solutions to degenerate kernel equations and matrix equations are consistent. Subsequently, the obtained results are extended to non-degenerate integral equations. …

Probabilistic time integration for semi-explicit PDAEs
R. Altmann, A. Moradi
https://arxiv.org/abs/2406.07220 https://arxiv.org/pdf/2…

Probabilistic time integration for semi-explicit PDAEs
This paper deals with the application of probabilistic time integration methods to semi-explicit partial differential-algebraic equations of parabolic type and its semi-discrete counterparts, namely semi-explicit differential-algebraic equations of index 2. The proposed methods iteratively construct a probability distribution over the solution of deterministic problems, enhancing the information obtained from the numerical simulation. Within this paper, we examine the efficacy of the randomized…

Model order reduction for seismic applications
Rhys Hawkins, Muhammad Hamza Khalid, Matthias Schlottbom, Kathrin Smetana
https://arxiv.org/abs/2406.07207 h…

Model order reduction for seismic applications
We propose a model order reduction approach to speed up the computation of seismograms, i.e. the solution of the seismic wave equation evaluated at a receiver location, for different model parameters. Our approach achieves a reduction of the unknowns by a factor of approximately 1000 for various numerical experiments for a 2D subsurface model of Groningen, the Netherlands, even if the wave speeds of the subsurface are relatively varied. Moreover, using parallel computing, the reduced model can …

A Well-Balanced Method for an Unstaggered Central Scheme, the two-space Dimensional Case
Yu-Chen Cheng, Christian Klingenberg, Rony Touma
https://arxiv.org/abs/2406.07185

A Well-Balanced Method for an Unstaggered Central Scheme, the two-space Dimensional Case
We develop a second-order accurate central scheme for the two-dimensional hyperbolic system of in-homogeneous conservation laws. The main idea behind the scheme is that we combine the well-balanced deviation method with the Kurganov-Tadmor (KT) scheme. The approach satisfies the well-balanced property and retains the advantages of KT scheme: Riemann-solver-free and the avoidance of oversampling on the regions between Riemann-fans. The scheme is implemented and applied to a number of numerical e…

Solving singular generalized eigenvalue problems. Part III: structure preservation
Michiel E. Hochstenbach, Christian Mehl, Bor Plestenjak
https://arxiv.org/abs/2406.07109

Solving singular generalized eigenvalue problems. Part III: structure preservation
In Parts I and II of this series of papers, three new methods for the computation of eigenvalues of singular pencils were developed: rank-completing perturbations, rank-projections, and augmentation. It was observed that a straightforward structure-preserving adaption for symmetric pencils was not possible and it was left as an open question how to address this challenge. In this Part III, it is shown how the observed issue can be circumvented by using Hermitian perturbations. This leads to str…

On the power of adaption and randomization
David Krieg, Erich Novak, Mario Ullrich
https://arxiv.org/abs/2406.07108 https://arxiv.org…

On the power of adaption and randomization
We present bounds between different widths of convex subsets of Banach spaces, including Gelfand and Bernstein widths. Using this, and some relations between widths and minimal errors, we obtain bounds on the maximal gain of adaptive and randomized algorithms over non-adaptive, deterministic ones for approximating linear operators on convex sets. Our results also apply to the approximation of embeddings into the space of bounded functions based on function evaluations, i.e., to sampling recover…

An efficient active-stress electromechanical isogeometric shell model for muscular thin film simulations
Michele Torre, Simone Morganti, Alessandro Nitti, Marco Donato de Tullio, Josef Kiendl, Francesco Silvio Pasqualini, Alessandro Reali
https://arxiv.org/abs/2406.07102

An efficient active-stress electromechanical isogeometric shell model for muscular thin film simulations
We propose an isogeometric approach to model the deformation of active thin films using layered, nonlinear, Kirchhoff Love shells. Isogeometric Collocation and Galerkin formulations are employed to discretize the electrophysiological and mechanical sub-problems, respectively, with the possibility to adopt different element and time-step sizes. Numerical tests illustrate the capabilities of the active stress based approach to effectively simulate the contraction of thin films in both quasi-stati…

Research on High-precision Detection Technology for Un-derground Space Information Data
Zuo Yanhong, Zhou Chao, Xia Shilong, Yang kun
https://arxiv.org/abs/2406.07045

Research on High-precision Detection Technology for Un-derground Space Information Data
The quality of underground space information data has become a major problem endangering the safety of underground space. After research and analysis, we found that the current high accuracy information data remote detection methods are limited to the detection of overground spaces objects, and are not applicable to the detection of various information data in underground space. In this paper, we analyze the spectral properties of the fractional-order differential (FDO) operator, and establish …

On inertial Levenberg-Marquardt type methods for solving nonlinear ill-posed operator equations
Antonio Leit\~ao, Joel C. Rabelo, Dirk A. Lorenz, Maximilian Winkler
https://arxiv.org/abs/2406.07044

On inertial Levenberg-Marquardt type methods for solving nonlinear ill-posed operator equations
In these notes we propose and analyze an inertial type method for obtaining stable approximate solutions to nonlinear ill-posed operator equations. The method is based on the Levenberg-Marquardt (LM) iteration. The main obtained results are: monotonicity and convergence for exact data, stability and semi-convergence for noisy data. Regarding numerical experiments we consider: i) a parameter identification problem in elliptic PDEs, ii) a parameter identification problem in machine learning; the …

Optimal Matrix-Mimetic Tensor Algebras via Variable Projection
Elizabeth Newman, Katherine Keegan
https://arxiv.org/abs/2406.06942 https://

Optimal Matrix-Mimetic Tensor Algebras via Variable Projection
Recent advances in {matrix-mimetic} tensor frameworks have made it possible to preserve linear algebraic properties for multilinear data analysis and, as a result, to obtain optimal representations of multiway data. Matrix mimeticity arises from interpreting tensors as operators that can be multiplied, factorized, and analyzed analogous to matrices. Underlying the tensor operation is an algebraic framework parameterized by an invertible linear transformation. The choice of linear mapping is cru…

A Fast Solver for Tridiagonal Toeplitz Systems with Multiple Right-Hand Sides
Shahin Hasanbeigi
https://arxiv.org/abs/2406.06734 https://

A Fast Solver for Tridiagonal Toeplitz Systems with Multiple Right-Hand Sides
In this work, we introduce a novel approach for solving tridiagonal Toeplitz systems with multiple right-hand sides.

Convergence of Subdivision Schemes and Smoothness of Refinable Functions on p-adic Fields
Athira N, Lineesh M C
https://arxiv.org/abs/2406.06628 https://…

Convergence of Subdivision Schemes and Smoothness of Refinable Functions on p-adic Fields
A systematic and comprehensive study of p-adic refinement equations and subdivision scheme associated with a finitely supported refinement mask are carried out in this paper. The Lq -convergence of the subdivision scheme is characterized in terms of the q-norm joint spectral radii of a collection of operators associated with the refinement mask. Also, the smoothness of complex-valued functions on Qp is investigated.

[2024-06-12 Wed (UTC), 13 new articles found for math.NA Numerical Analysis]

This https://arxiv.org/abs/2403.19433 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Puzzle game: Prediction and Classification of Wordle Solution Words
In MCM/ICM 2023, we proposed a new result prediction model for the popular game Wordle launched by The New York Times. We first preprocessed the raw data and then established a prediction model based on ARIMA to predict the number of report results as of March 1, 2023. We selected word usage frequency, word information entropy, and the number of repeated letters contained in the word as the attributes of the word, and conducted a correlation analysis between these three attributes and the perce…