A Survey on Consortium Blockchain Consensus Mechanisms

Blockchain is a distributed ledger that is decentralized, immutable, and transparent, which maintains a continuously growing list of transaction records ordered into blocks. As the core of blockchain, the consensus algorithm is an agreement to validate the correctness of blockchain transactions. For example, Bitcoin is a public blockchain where each node in Bitcoin uses the Proof of Work (PoW) algorithm to reach a consensus by competing to solve a puzzle. Unlike a public blockchain, a consortium blockchain is an enterprise-level blockchain that does not contend with the issues of creating a resource-saving global consensus protocol. This paper highilights several state-of-the art solutions in consensus algorithms for enterprise blockchain. For example, the HyperLedger by Linux Foundation includes implementing Practical Byzantine Fault Tolerance (PBFT) as the consensus algorithm. PBFT can tolerate a range of malicious nodes and reach consensus with quadratic complexity. Another consensus algorithm, HotStuff, implemented by Facebook Libra project, has achieved linear complexity of the authenticator. This paper presents the operational mechanisms of these and other consensus protocols, and analyzes and compares their advantages and drawbacks.Comment: under submissio

The influence of different intensity of monsoon on typhoon precipitation: a comparative study of typhoons Soudelor and Maria

In this paper, multiple sets of reanalysis datasets are used to analyze the intensity of the Asian summer monsoon from 1979 to 2021. Typhoon Soudelor (No. 1513) and Typhoon Maria (No. 1808) were selected from the weak monsoon year 2015 and the strong monsoon year 2018, both of which were generated in the Northwest Pacific in July and made landfall in South China. The Weather Research and Forecasting Model (WRF) was used to simulate the two typhoons, starting 48 h prior to their landfall. The reasons for the differences in precipitation and how the monsoon affects typhoon precipitation in this process are analyzed from the aspects of monsoon background, ambient weather systems, typhoon thermodynamic structure, and water vapor conditions. The analysis shows that the circulation of Soudelor was stable and maintained for a long time. Despite existing in the background of a weak monsoon, the monsoon flow was able to reach the key area affecting typhoons and inject enough warm and moist flow to affect Soudelor. Combined with the analysis of typhoon structure, the strong water vapor transport of Soudelor and increased low-level convergence were conducive to the formation of typhoon-related rainstorms. The monsoon appeared to provide environmental conditions favorable for typhoon precipitation, resulting in a wide range of precipitation and heavy precipitation. Typhoon Maria developed and changed rapidly, moved rapidly, and the precipitation maintained itself for a relatively short time. The monsoon flow was not transported into Maria, resulting in insufficient water vapor inside Maria, which prevented the strengthening of typhoon precipitation. The precipitation of Maria mainly came from the dynamics of the typhoon itself and was not affected by the monsoon. In addition, this study defines an area on the southwest side of the typhoon moving with the center of the typhoon as the key area affecting typhoons. The characteristics of this area can be simply linked to typhoon precipitation, which can be considered an important research area for future analysis and prediction of typhoon precipitation

SafeLight: A Reinforcement Learning Method toward Collision-free Traffic Signal Control

Traffic signal control is safety-critical for our daily life. Roughly one-quarter of road accidents in the U.S. happen at intersections due to problematic signal timing, urging the development of safety-oriented intersection control. However, existing studies on adaptive traffic signal control using reinforcement learning technologies have focused mainly on minimizing traffic delay but neglecting the potential exposure to unsafe conditions. We, for the first time, incorporate road safety standards as enforcement to ensure the safety of existing reinforcement learning methods, aiming toward operating intersections with zero collisions. We have proposed a safety-enhanced residual reinforcement learning method (SafeLight) and employed multiple optimization techniques, such as multi-objective loss function and reward shaping for better knowledge integration. Extensive experiments are conducted using both synthetic and real-world benchmark datasets. Results show that our method can significantly reduce collisions while increasing traffic mobility.Comment: Accepted by AAAI 2023, appendix included. 9 pages + 5 pages appendix, 12 figures, in Proceedings of the Thirty-Seventh AAAI Conference on Artificial Intelligence (AAAI'23), Feb 202

catena-Poly[[aqua­dipyridine­copper(II)]-μ-fumarato]

The title compound, [Cu(C4H2O4)(C5H5N)2(H2O)]n, is a one-dimensional coordination polymer based on pyridine and fumarate ligands. Each CuII cation is coordinated by two carboxyl­ate O atoms belonging to two fumarate anions, two N atoms from two pyridine mol­ecules and one water mol­ecule, in a square-based pyramidal geometry. Each fumarate anion bridges two CuII cations through the two carboxyl­ate groups in a bis-monodentate fashion to form a one-dimensional polymeric chain along the c axis. Neighbouring chains are linked together to form a two-dimensional network parallel to the ac plane via hydrogen bonding inter­actions between uncoordinated carboxyl­ate O atoms and coordinated water mol­ecules of adjecent chains

rac-7,7′,9,9′-Tetra­phenyl-9a,9a′-bi(7,8,9,9a-tetra­hydro-6aH-penta­leno[1,2,3-ij]naphthalen-8-one)

The racemic title compound, C54H38O2, consists of two C-linked penta­leno[1,2,3-ij]naphthalenone moieties, the crowded aryl ring substitution on the cyclo­pentane rings forcing the two segments to assume a conformation which has pseudo-twofold rotational symmetry, with a dihedral angle between the naphthalene substituent groups of 55.30 (8)°. In each segment, the two phenyl rings have different conformational orientations, with inter-ring dihedral angles of 34.7 (2) and 49.63 (16)°. Each cyclo­pentane ring has the same relative configuration in its four chiral centres and together with the fused naphthalene ring assumes an overall chair-like conformation

A Facile Synthesis of ZnCo\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e Nanocluster Particles and the Performance as Anode Materials for Lithium Ion Batteries

ZnCo2O4 nanocluster particles (NCPs) were prepared through a designed hydrothermal method, with the assistance of a surfactant, sodium dodecyl benzene sulfonate. The crystalline structure and surface morphology of ZnCo2O4 were investigated by XRD, XPS, SEM, TEM, and BET analyses. The results of SEM and TEM suggest a clear nanocluster particle structure of cubic ZnCo2O4 (~100 nm in diameter), which consists of aggregated primary nanoparticles (~10 nm in diameter), is achieved. The electrochemical behavior of synthesized ZnCo2O4 NCPs was investigated by galvanostatic discharge/charge measurements and cyclic voltammetry. The ZnCo2O4 NCPs exhibit a high reversible capacity of 700 mAh g−1 over 100 cycles under a current density of 100 mA g−1 with an excellent coulombic efficiency of 98.9% and a considerable cycling stability. This work demonstrates a facile technique designed to synthesize ZnCo2O4 NCPs which show great potential as anode materials for lithium ion batteries

The activation of grammaticalized meaning in L2 processing: Toward an explanation of the morphological congruency effect

© 2015, © The Author(s) 2015. Objectives: The study was intended to test the hypothesis that L2 speakers have difficulty in automatically activating a grammaticalized L2 meaning that is not morphologically marked in L1. Methodology: The study consisted of three experiments. A sentence–picture matching task was designed to assess the activation of grammaticalized meaning. The participants were asked to judge if a sentence correctly described the physical relationships of three objects in a picture. Hidden in the stimuli that required a positive response was a number agreement manipulation whereby a noun phrase in the sentence may agree or disagree with the number of objects in the picture. A number disagreement effect, as shown in a delay in producing a positive response on items of number disagreement was used to assess automatic activation of number meanings. Data and Analysis: The data constituted reaction times and accuracy rates from 32 English native speakers, 36 Chinese native speakers, 54 Chinese–English bilinguals, and 26 Russian–English bilinguals. Analyses of variance were performed in analyzing these data. Findings: The results showed a number disagreement effect in L1 and L2 among Russian English as a second language (ESL) speakers only. Chinese ESL speakers showed no difference between the two critical conditions in either language. A follow-up experiment showed that Chinese ESL speakers had no difficulty in automatically activating number meanings which were expressed lexically in English sentence processing. These findings provided support for the idea that the well documented difficulty L2 learners have in learning incongruent L2 inflectional morphemes may have to do with their difficulty in automatically activating a grammaticalized meaning that is not grammaticalized in their L1. Originality: The sentence–picture matching task represented a unique and effective approach to the study of the activation of grammaticalized meanings. Significance: The findings from the study represented some first psycholinguistic evidence regarding the activation of grammaticalized meanings among non-native speakers