Mysticeti: Low-Latency DAG Consensus with Fast Commit Path

We introduce Mysticeti-C a byzantine consensus protocol with low-latency and high resource efficiency. It leverages a DAG based on Threshold Clocks and incorporates innovations in pipelining and multiple leaders to reduce latency in the steady state and under crash failures. Mysticeti-FPC incorporates a fast commit path that has even lower latency. We prove the safety and liveness of the protocols in a byzantine context. We evaluate Mysticeti and compare it with state-of-the-art consensus and fast path protocols to demonstrate its low latency and resource efficiency, as well as more graceful degradation under crash failures. Mysticeti is the first byzantine protocol to achieve WAN latency of 0.5s for consensus commit, at a throughput of over 50k TPS that matches the state-of-the-art

Twins: BFT Systems Made Robust

This paper presents Twins, an automated unit test generator of Byzantine attacks. Twins implements three types of Byzantine behaviors: (i) leader equivocation, (ii) double voting, and (iii) losing internal state such as forgetting "locks" guarding voted values. To emulate interesting attacks by a Byzantine node, it instantiates twin copies of the node instead of one, giving both twins the same identities and network credentials. To the rest of the system, the twins appear indistinguishable from a single node behaving in a "questionable" manner. Twins can systematically generate Byzantine attack scenarios at scale, execute them in a controlled manner, and examine their behavior. Twins scenarios iterate over protocol rounds and vary the communication patterns among nodes. Twins runs in a production setting within DiemBFT where it can execute 44M Twins-generated scenarios daily. Whereas the system at hand did not manifest errors, subtle safety bugs that were deliberately injected for the purpose of validating the implementation of Twins itself were exposed within minutes. Twins can prevent developers from regressing correctness when updating the codebase, introducing new features, or performing routine maintenance tasks. Twins only requires a thin wrapper over DiemBFT, we thus envision other systems using it. Building on this idea, one new attack and several known attacks against other BFT protocols were materialized as Twins scenarios. In all cases, the target protocols break within fewer than a dozen protocol rounds, hence it is realistic for the Twins approach to expose the problems

Synthesis and properties of the materials obtained by SHS mode for radiation protection

The article shows the process of protective composite materials manufacturing. Also, the analysis of experimental results concerning the composite materials protective properties is given. The advantages of SHS method are considered in comparison with traditional materials. The uniqueness of SHS obtained products based on combination of nuclear-physical properties and parameters is presented

Sui Lutris: A Blockchain Combining Broadcast and Consensus

Sui Lutris is the first smart-contract platform to sustainably achieve sub-second finality. It achieves this significant decrease in latency by employing consensusless agreement not only for simple payments but for a large variety of transactions. Unlike prior work, Sui Lutris neither compromises expressiveness nor throughput and can run perpetually without restarts. Sui Lutris achieves this by safely integrating consensuless agreement with a high-throughput consensus protocol that is invoked out of the critical finality path but makes sure that when a transaction is at risk of inconsistent concurrent accesses its settlement is delayed until the total ordering is resolved. Building such a hybrid architecture is especially delicate during reconfiguration events, where the system needs to preserve the safety of the consensusless path without compromising the long-term liveness of potentially misconfigured clients. We thus develop a novel reconfiguration protocol, the first to show the safe and efficient reconfiguration of a consensusless blockchain. Sui Lutris is currently running in production as part of a major smart-contract platform. Combined with the Move Programming language it enables the safe execution of smart contracts that expose objects as a first-class resource. In our experiments Sui Lutris achieves latency lower than 0.5 seconds for throughput up to 5,000 certificates per second (150k ops/s with bundling), compared to the state-of-the-art real-world consensus latencies of 3 seconds. Furthermore, it gracefully handles validators crash-recovery and does not suffer visible performance degradation during reconfiguration

Pilot studies of the unique highland palsa mire in Western Sayan (Tuva Republic, Russian Federation)

In contrast to the well-studied West Siberian sector of frozen bogs in the Russian Arctic, the frozen mound bogs (so-called “palsas”) on the highlands of Southern Siberia have not yet been studied, but they are suspected to be even more sensitive to ongoing climate change. This article provides the pilot study on palsa mire Kara-Sug in the highland areas of Western Sayan mountain system, Tuva Republic. The study focuses on the current state of palsa mire and surrounding landscapes, providing wide range of ecological characteristics while describing ongoing transformations of natural landscapes under a changing climate. The study used a variety of field and laboratory methods: the integrated landscape-ecological approach, the study of peat deposits, geobotanical analysis, and modern analysis of the chemical composition of water, peat, and soils. The study shows that highland palsa mires are distinguished by their compactness and high variety of cryogenic landforms leading to high floristic and ecosystem diversity compared with lowland palsa mires. This information brings new insights and contributes to a better understanding of extrazonal highland palsa mires, which remain a “white spot” in the global environmental sciences

The development of Kondratieff’s theory of long waves: the place of the AI economy humanization in the ‘competencies-innovations-markets’ model

Abstract The motivation to conduct this study is related to the uncertainty of the impact of the AI economy on the economic cycle and the need to unlock the potential of Industry 4.0 in stabilizing the global economic system amid a series of crises. The article discusses the fundamental issues of the emergence of a new theory related to the evolution of Kondratieff waves in the context of modern drivers of long-term economic development (MANBRIC technologies), taking into account the acceleration of the development of innovations and competencies. The spiraling dynamics of the co-development of competencies and the expansion of new markets are shown, which makes it possible to transform the decline phase of the Kondratieff wave into a similar linear process of maintaining economic growth rates close to the existing ones. As a result, based on the authors’ model “competencies-innovations-markets”, it is proved that subject to humanization, the AI economy allows the reduction of the cyclical nature of the world economic system. The main idea of the article is to smooth out Kondratieff’s long waves due to the humanization of the AI economy

A Study of Directional Patterns of Ultrasonic Parametric Array

The paper presents results of numerical calculations and experimental data on the directional pattern of two 38-element parametric arrays composed of ultrasound sources. Two types of antenna arrays are considered, namely with parallel and coaxial connections of ultrasonic transducers (elements). The results of selecting and functional testing of unit elements are described in this paper. It is found that in the coaxial element connection of the antenna array, the level of side lobes is higher than that in the paralel element connection

Impacts of environmental change on biodiversity and vegetation dynamics in Siberia

Biological diversity is the basis for, and an indicator of biosphere integrity. Together with climate change, its loss is one of the two most important planetary boundaries. A halt in biodiversity loss is one of the UN Sustainable Development Goals. Current changes in biodiversity in the vast landmass of Siberia are at an initial stage of inventory, even though the Siberian environment is experiencing rapid climate change, weather extremes and transformation of land use and management. Biodiversity changes affect traditional land use by Indigenous People and multiple ecosystem services with implications for local and national economies. Here we review and analyse a large number of scientific publications, which are little known outside Russia, and we provide insights into Siberian biodiversity issues for the wider international research community. Case studies are presented on biodiversity changes for insect pests, fish, amphibians and reptiles, birds, mammals and steppe vegetation, and we discuss their causes and consequence