arXiv subjects

Alexander Ivanov

Publications and source records attributed to Alexander Ivanov.

At least 19 recordsLinked to original sources

arXiv2026

KVAE: Family of Tokenizers for Multimodal Generative Models

Latent diffusion modeling (LDM), a prominent paradigm, utilizes tokenizers to map input signal to compressed representation. This dependency positions tokenizer as an integral part of generation process itself, since it affects learning speed, quality of synthesized samples and lay foundation for later applications. This report presents series of KVAE tokenizers for audio, image and video, all designed for subsequent text-conditioned generation: KVAE-Audio, a continuous full-band 48 kHz tokenizer with a 50 Hz latent of 64 channels; KVAE-3D -- two causal video tokenizers for 4x16x16 and 4x8x8 compression; KVAE-2D, an image model, compressing input by factor of 8 with 32 channels. We demonstrate that reconstruction (PSNR, LPIPS, PESQ, etc.) and generation results on objective (Frechet Distance, CLIP score, CLAP score, etc.) and subjective (side-by-side evaluation) metrics matches or surpasses frontier opensource tokenizers, such as VAEs from Wan-2.2, HunyuanVideo-1.5, FLUX.2, MovieGen, StableAudio and MMAudio. Considering difficulty of development, we share with community training details, model selection method and ablation on design choices. The code is publicly available at https://github.com/kandinskylab/kvae and https://github.com/kandinskylab/kvae-audio.

cs.CV↗

arXiv2026

Benchmarks in Leipzig

Between April 1 and May 15, 2026, a group of 49 mathematicians compiled a dataset of research-level mathematics questions with known answers. Most of the work was done during the 3-day workshop *Benchmarks in Leipzig* with 35 participants at the Max Planck Institute for Mathematics in the Sciences in Leipzig, Germany. We present the resulting collection of 100 questions. We evaluated these questions in three stages: a single attempt by five state-of-the-art LLMs, followed by a 20-runs-per-model evaluation with three of these models, and finally a 3-run attempt with two heavy-thinking models. After Stage 1, 41 questions remained completely unsolved; after Stage 2, this count dropped to 16; and we concluded Stage 3 with only 2 unsolved questions. This demonstrates that the mathematical reasoning capabilities of LLMs are becoming impressive.

math.HO↗

arXiv2023

A collection of the data coding means and event coding means multiplexed over and inside the 1000BASE-T PMA sublayer

This collection bundles the following memos dedicated to Gigabit Ethernet, type 1000BASE-T: [1] "Data Coding Means and Event Coding Means Multiplexed Over the 1000BASE-T PMA Sublayer" (extends the IEEE 802.3ab protocol via the so called draft design approach, pp. 1-4); [2] "Spreading the Constellation Coverage of the Draft Data Coding Means and Event Coding Means Multiplexed Over the 1000BASE-T PMA Sublayer" (spread design, pp. 5-8); [3] "Rethinking the Constellation Model of the Spread Data Coding Means and Event Coding Means Multiplexed Over the 1000BASE-T PMA Sublayer" (bubbled design, pp. 9-12); [4] "Data Coding Means and Event Coding Means Multiplexed Inside the 1000BASE-T PMA Sublayer" (stellarial design, pp. 13-16); [5] "Design Details, Usable and Useful, Related to the Data Coding Means and Event Coding Means Multiplexed Inside the 1000BASE-T PMA Sublayer" (dynamic design, pp. 17-20); [6] "Design Limits, Implicit and Explicit, Related to the Data Coding Means and Event Coding Means Multiplexed Inside the 1000BASE-T PMA Sublayer" (optimal design, pp. 21-24); and [7] "Extra Material, Including Advanced, Related to the Data Coding Means and Event Coding Means Multiplexed Inside the 1000BASE-T PMA Sublayer" (advanced design, pp. 25-28).

cs.IT↗

arXiv2023

Database of semiconductor point-defect properties for applications in quantum technologies

Solid-state point defects are attracting increasing attention in the field of quantum information science, because their localized states can act as a spin-photon interface in devices that store and transfer quantum information, which have been used for applications in quantum computing, sensing, and networking. In this work we have performed high-throughput calculations of over 50,000 point defects in various semiconductors including diamond, silicon carbide, and silicon. Focusing on quantum applications, we characterize the relevant optical and electronic properties of these defects, including formation energies, spin characteristics, transition dipole moments, zero-phonon lines. We find 2331 composite defects which are stable in intrinsic silicon, which are then filtered to identify many new optically bright telecom spin qubit candidates and single-photon sources. All computed results and relaxed defect structures are made publicly available online at quantumdefects.com, a living database of defect characteristics which will be continually expanded with new defects and properties, and will enable researchers to select defects tailored to their applications.

quant-ph↗

arXiv2023

A collection of the data coding means and event coding means multiplexed over the 100BASE-T1 PMA sublayer, over a 10BASE-T/Te MAU-like entity, over a 10BASE-T1S PMA-like entity, and over the 10BASE-T1L PMA sublayer

This collection bundles the following memos dedicated to Fast-speed (100 Mb/s) and Original-speed (10 Mb/s) Ethernet protocols, including upgradeable from Manchester (ME/DME) into Like-a-Manchester (LaM) encoding schemes: [1] "Data Coding Means and Event Coding Means Multiplexed Over the 100BASE-T1 PMA Sublayer" (extends the IEEE 802.3bw protocol, uses a non-LaM encoding, present at pp. 1-4); [2] "Data Coding Means and Event Coding Means Multiplexed Over a 10BASE-T/Te MAU-like Entity" (IEEE 802.3i/az, LaM-based, pp. 5-8); [3] "Data Coding Means and Event Coding Means Multiplexed Over a 10BASE-T1S PMA-like Entity" (IEEE 802.3cg's Clause 147, LaM-based, pp. 9-12); and [4] "Data Coding Means and Event Coding Means Multiplexed Over the 10BASE-T1L PMA Sublayer" (IEEE 802.3cg's Clause 146, non-LaM, pp. 13-16).

cs.IT↗

arXiv2023

A collection of memos dedicated to exact base-21 (EBTO) and quasi base-21 (QBTO) codes

This collection bundles the following memos dedicated to the so called exact base-21 (EBTO) and quasi base-21 (QBTO) serial transport codes: [1] "Base-21 Scrambling" (discusses about EBTO codes, present at pp. 1-4 in the bundle); [2] "Base-21 Word Alignment and Boundary Detection" (EBTO, pp. 5-8); [3] "Quasi Base-21 Words" (QBTO, pp. 9-12); [4] "Quasi Base-21 Words Generated Compactly" (QBTO, pp. 13-16); and [5] "Quasi Base-21 Words Balanced on the Framework" (QBTO, pp. 17-20).

cs.IT↗

arXiv2023

A collection of the data coding means and event coding means multiplexed over the 1000BASE-T1, 10GBASE-T, 10GBASE-KR, MultiGBASE-T1, 25G/40GBASE-T, 2.5G/5GBASE-T, 100GBASE-R, 10G/25G-EPON, and 10GPASS-XR microframes

This collection bundles the following memos dedicated to Ethernet protocols featuring a very long binary transport word (microframe): [1] "Data Coding Means and Event Coding Means Multiplexed Over the 1000BASE-T1 PCS Payload" (extends the IEEE 802.3bp protocol, present at pp. 1-4 in the bundle); [2] "Data Coding Means and Event Coding Means Multiplexed Over the 10GBASE-T PCS Payload" (IEEE 802.3an, pp. 5-8); [3] "Data Coding Means and Event Coding Means Multiplexed Over the 10GBASE-KR PCS Payload" (IEEE 802.3ap, pp. 9-12); [4] "Data Coding Means and Event Coding Means Multiplexed Over the MultiGBASE-T1 PCS Payload" (IEEE 802.3ch, pp. 13-16); [5] "Data Coding Means and Event Coding Means Multiplexed Over the 25G/40GBASE-T FEC Input" (IEEE 802.3bq, pp. 17-20); [6] "Data Coding Means and Event Coding Means Multiplexed Over the 2.5G/5GBASE-T FEC Input" (IEEE 802.3bz, pp. 21-24); [7] "Data Coding Means and Event Coding Means Multiplexed Over the 100GBASE-R FEC Inputs" (IEEE 802.3bj, pp. 25-28); [8] "Data Coding Means and Event Coding Means Multiplexed Over the 10G/25G-EPON FEC Inputs" (IEEE 802.3av/ca, pp. 29-32); and [9] "Data Coding Means and Event Coding Means Multiplexed Over the 10GPASS-XR FEC Inputs" (IEEE 802.3bn, pp. 33-36).

cs.NI↗

arXiv2022

Gromov-Hausdorff Distance and Borsuk Number

The aim of this paper is to demonstrate relations between Gromov-Hausdorff distance properties and the Borsuk Conjecture. The Borsuk number of a given bounded metric space $X$ is the infimum of cardinal numbers $n$ such that $X$ can be partitioned into $n$ smaller parts (in the sense of diameter). An exact formula for the Gromov-Hausdorff distance between bounded metric spaces is obtained under the assumptions that the diameter and the cardinality of one space is less than the diameter and the Borsuk number of the other one, respectively. Using Bacon equivalence results between Lusternik-Schnirelmann and Borsuk Problems several corollaries are obtained.

math.GN↗

arXiv2021

Manifold Hypothesis in Data Analysis: Double Geometrically-Probabilistic Approach to Manifold Dimension Estimation

Manifold hypothesis states that data points in high-dimensional space actually lie in close vicinity of a manifold of much lower dimension. In many cases this hypothesis was empirically verified and used to enhance unsupervised and semi-supervised learning. Here we present new approach to manifold hypothesis checking and underlying manifold dimension estimation. In order to do it we use two very different methods simultaneously - one geometric, another probabilistic - and check whether they give the same result. Our geometrical method is a modification for sparse data of a well-known box-counting algorithm for Minkowski dimension calculation. The probabilistic method is new. Although it exploits standard nearest neighborhood distance, it is different from methods which were previously used in such situations. This method is robust, fast and includes special preliminary data transformation. Experiments on real datasets show that the suggested approach based on two methods combination is powerful and effective.

cs.LG↗

arXiv2019

Solution to Generalized Borsuk Problem in Terms of the Gromov-Hausdorff Distances to Simplexes

In the present paper the following Generalized Borsuk Problem is studied: Can a given bounded metric space $X$ be partitioned into a given number $m$ (probably an infinite one) of subsets, each of which has a smaller diameter than $X$? We give a complete answer to this question in terms of the Gromov-Hausdorff distance from $X$ to a simplex of cardinality $m$ and having a diameter less than $X$. Here a simplex is a metric space, all whose non-zero distances are the same.

math.MG↗

arXiv2018

Isometry Group of Gromov--Hausdorff Space

The present paper is devoted to investigation of the isometry group of the Gromov-Hausdorff space, i.e., the metric space of compact metric spaces considered up to an isometry and endowed with the Gromov-Hausdorff metric. The main goal is to present a proof of the following theorem by George Lowther (2015): The isometry group of the Gromov-Hausdorff space is trivial. Unfortunately, the author himself has not publish an accurate text for 2 years passed from the publication of draft (that is full of excellent ideas mixed with unproved and wrong statements) in the https://mathoverflow.net/ blog (see the exact reference in he bibliography).

math.MG↗

arXiv2018

Secure Minimum Time Planning Under Environmental Uncertainty: an Extended Treatment

Cyber Physical Systems (CPS) are becoming ubiquitous and affect the physical world, yet security is seldom at the forefront of their design. This is especially true of robotic control algorithms which seldom consider the effect of a cyber attack on mission objectives and success. This work presents a secure optimal control algorithm in the face of a cyber attack on a robot's knowledge of the environment. This work focuses on cyber attack, but the results generalize to incomplete or outdated information of an environment. This work fuses ideas from robust control, optimal control, and sensor based planning to provide a generalization of stopping distance in 3D. The planner is implemented in simulation and its properties are analyzed.

cs.RO↗

arXiv2017

Evaluating 35 Methods to Generate Structural Connectomes Using Pairwise Classification

There is no consensus on how to construct structural brain networks from diffusion MRI. How variations in pre-processing steps affect network reliability and its ability to distinguish subjects remains opaque. In this work, we address this issue by comparing 35 structural connectome-building pipelines. We vary diffusion reconstruction models, tractography algorithms and parcellations. Next, we classify structural connectome pairs as either belonging to the same individual or not. Connectome weights and eight topological derivative measures form our feature set. For experiments, we use three test-retest datasets from the Consortium for Reliability and Reproducibility (CoRR) comprised of a total of 105 individuals. We also compare pairwise classification results to a commonly used parametric test-retest measure, Intraclass Correlation Coefficient (ICC).

q-bio.NC↗

arXiv2017

An Extended Consideration of Joint Exploration and Tracking: JET

Autonomous exploration and multi-object tracking by a team of agents have traditionally been considered as two separate, yet related, problems which are usually solved in two phases: an exploration phase then a tracking phase. The exploration problem is usually viewed through an information theoretic framework where a robotic agent attempts to gather as much information about the environment or an Object of Interest (OI). Conversely, the tracking problem attempts to maintain precise location information about an OI over time. This work proposes a single framework which enables the multi-robot multi-object problem to be solved simultaneously. A hierarchical architecture is used to coordinate robotic agents in the tracking of multiple OIs while simultaneously allowing the task to remain computationally efficient. The primary contributions of this work are a probabilistic constraint on the tracked OIs' covariances guarantees tracking performance throughout the entire mission. The automatic discovery of new OIs, a seamless transition to guaranteed tracking of discovered OIs, and the automatic balancing of exploration with the requirements of tracking.

cs.RO↗

arXiv2017

An Extended Treatment of Uncertainty Constrained robotic Exploration: An Integrated Exploration Planner

Efficient robotic exploration of unknown, sensor limited, global-information-deficient environments poses unique challenges to path planning algorithms. In these difficult environments, no deterministic guarantees on path completion and mission success can be made in general. Integrated Exploration (IE), which strives to combine localization and exploration, must be solved in order to create an autonomous robotic system capable of long term operation in new and challenging environments. This paper formulates a probabilistic framework which allows the creation of exploration algorithms providing probabilistic guarantees of success. A novel connection is made between the Hamiltonian Path Problem and exploration. The Guaranteed Probabilistic Information Explorer (G-PIE) is developed for the IE problem, providing a probabilistic guarantee on path completion, and asymptotic optimality of exploration. A receding horizon formulation, dubbed RH-PIE, is presented which addresses the exponential complexity present in G-PIE. Finally, RH-PIE planner is verified via autonomous, hardware-in-the-loop experiments.

cs.RO↗

arXiv2017

Structural Connectome Validation Using Pairwise Classification

In this work, we study the extent to which structural connectomes and topological derivative measures are unique to individual changes within human brains. To do so, we classify structural connectome pairs from two large longitudinal datasets as either belonging to the same individual or not. Our data is comprised of 227 individuals from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and 226 from the Parkinson's Progression Markers Initiative (PPMI). We achieve 0.99 area under the ROC curve score for features which represent either weights or network structure of the connectomes (node degrees, PageRank and local efficiency). Our approach may be useful for eliminating noisy features as a preprocessing step in brain aging studies and early diagnosis classification problems.

q-bio.NC↗

arXiv2017

Side resonances and metastable excited state of NV- center in diamond

We discuss the side resonances of optically detected magnetic resonance in diamond crystal and propose the new approach to the calculation of hyperfine interaction in composed system, consisted of negatively charged nitrogen-vacancy NV- center and nearby 13C nuclear spin. Energy levels and spin states are obtained by new method. The base of this method is the using of complete set of commuting operators. In zero magnetic field, predicted the existence of metastable excited state.

cond-mat.mes-hall↗

arXiv2016

Steiner Ratio and Steiner-Gromov Ratio of Gromov-Hausdorff Space

In the present paper we investigate the metric space $\cal M$ consisting of isometry classes of compact metric spaces, endowed with the Gromov-Hausdorff metric. We show that for any finite subset $M$ from a sufficiently small neighborhood of a generic finite metric space, providing $M$ consists of finite metric spaces with the same number of points, each Steiner minimal tree in $\cal M$ connecting $M$ is a minimal filling for $M$. As a consequence, we prove that the both Steiner ratio and Gromov-Steiner ratio of $\cal M$ are equal to $1/2$.

math.MG↗