Whispering Vortices

Experiments indicating the excitation of whispering gallery type electromagnetic modes by a vortex moving in an annular Josephson junction are reported. At relativistic velocities the Josephson vortex interacts with the modes of the superconducting stripline resonator giving rise to novel resonances on the current-voltage characteristic of the junction. The experimental data are in good agreement with analysis and numerical calculations based on the two-dimensional sine--Gordon model.Comment: 5 pages, 5 figures, text shortened to fit 4 pages, correction of typo

The methods of the intensification of the GTE discs and shafts hard materials turning

Сформульовано проблему підвищення ефективності виготовлення дисків і валів ГТД за рахунок інтенсифікації точіння. Розглянуто перспективи використання матеріалів у літакобудуванні. Надано оцінку об’єму використання токарних операцій у механообробні дисків і валів ГТД. Запропоновано феноменологічну модель інтенсифікації процесу точіння важкооброблюваних матеріалів. Стисло розглянуто основні методи вдосконалення процесу точіння. Зроблено огляд прогресивних комбінованих методів обробки різанням важкооброблюваних матеріалів. Зроблено висновок про актуальність дослідження методу безпосереднього управління контактними і тепловими явищами для інтенсифікації токарної обробки ТОМ.Purpose. Search for promising ways to intensify of the GTE discs and shafts hard materials turning. Analysis of the scientific advances in this field. Specification purpose of scientific research aimed at the intensification of turning. Design/methodology/approach. The problem of increasing the efficiency of the GTE disks and shafts production through the intensification of the turning is still relevant because of the tendency of materials used in aircraft engine. With regard to the manufacturing processes of the gas turbine engines discs and shafts, the proportion of turning operations in the structure of some of them reaches 60%. The authors offer the phenomenological model of the intensification of difficult to cut materials turning and describe in short the basic methods of the cutting process improving. A review of the progressive combined machining methods of difficult to machine materials detects the presence of significant shortcomings. For a more elegant technical solution proposed the method of the direct control of contact and thermal phenomena for intensification of the difficult to cut materials turning. Findings. In order to intensify the turning of the GTE discs and shafts necessary to investigate the possibility of implementing the method of direct control of contact and thermal phenomena during processing. Originality/value. The phenomenological model of the intensification of difficult to cut materials turning is offered. The purpose of scientific research aimed at the intensification of turning is specified.Сформулирована проблема повышения эффективности производства дисков и валов ГТД за счет интенсификации точения. Рассмотрены перспективы использования материалов в авиастроении. Дана оценка объема применения токарных операций в механообработке дисков и валов ГТД. Предложена феноменологическая модель интенсификации процесса точения труднообрабатываемых материалов. Кратко рассмотрены основные методы совершенствования процесса резания. Выполнен обзор прогрессивных комбинированных методов обработки резанием труднообрабатываемых материалов. Сделан вывод об актуальности исследования метода непосредственного управления контактными и тепловыми явлениями для интенсификации токарной обработки труднообрабатываемых материалов

MiniHack the Planet: A Sandbox for Open-Ended Reinforcement Learning Research

Progress in deep reinforcement learning (RL) is heavily driven by the availability of challenging benchmarks used for training agents. However, benchmarks that are widely adopted by the community are not explicitly designed for evaluating specific capabilities of RL methods. While there exist environments for assessing particular open problems in RL (such as exploration, transfer learning, unsupervised environment design, or even language-assisted RL), it is generally difficult to extend these to richer, more complex environments once research goes beyond proof-of-concept results. We present MiniHack, a powerful sandbox framework for easily designing novel RL environments. MiniHack is a one-stop shop for RL experiments with environments ranging from small rooms to complex, procedurally generated worlds. By leveraging the full set of entities and environment dynamics from NetHack, one of the richest grid-based video games, MiniHack allows designing custom RL testbeds that are fast and convenient to use. With this sandbox framework, novel environments can be designed easily, either using a human-readable description language or a simple Python interface. In addition to a variety of RL tasks and baselines, MiniHack can wrap existing RL benchmarks and provide ways to seamlessly add additional complexity

Insights from the NeurIPS 2021 NetHack Challenge

In this report, we summarize the takeaways from the first NeurIPS 2021 NetHack Challenge. Participants were tasked with developing a program or agent that can win (i.e., ‘ascend’ in) the popular dungeon-crawler game of NetHack by interacting with the NetHack Learning Environment (NLE), a scalable, procedurally generated, and challenging Gym environment for reinforcement learning (RL). The challenge showcased community-driven progress in AI with many diverse approaches significantly beating the previously best results on NetHack. Furthermore, it served as a direct comparison between neural (e.g., deep RL) and symbolic AI, as well as hybrid systems, demonstrating that on NetHack symbolic bots currently outperform deep RL by a large margin. Lastly, no agent got close to winning the game, illustrating NetHack’s suitability as a long-term benchmark for AI research