SoK: Blockchain Decentralization

Blockchain empowers a decentralized economy by enabling distributed trust in a peer-to-peer network. However, surprisingly, a widely accepted definition or measurement of decentralization is still lacking. We explore a systematization of knowledge (SoK) on blockchain decentralization by comprehensively analyzing existing studies in various aspects. First, we establish a taxonomy for analyzing blockchain decentralization in the five facets of consensus, network, governance, wealth, and transaction. We find a lack of research on the transaction aspects that closely characterize user behavior. Second, we apply Shannon entropy in information theory to propose a decentralization index for blockchain transactions. We show that our index intuitively measures levels of decentralization in peer-to-peer transactions by simulating blockchain token transfers. Third, we apply our index to empirically analyze the dynamics of DeFi token transfers by three methods of description, prediction, and causal inference. In the descriptive analysis, we observe that levels of decentralization converge inter-temporally, regardless of the initial levels. A comparative study across DeFi applications shows that exchange and lending are more decentralized than payment and derivatives across DeFi applications. Second, in the predictive analysis, we also discover that a greater return of Ether, the native coin of the Ethereum blockchain, predicts a greater transaction decentralization in stablecoin that include Ether as collateral. Third, in an event study of causal inference, we find the change of Ethereum Transaction Fee Mechanism to EIP-1559 significantly changes the decentralization level of DeFi transactions. Finally, we identify future research directions

Positive solutions of higher order fractional integral boundary value problem with a parameter

In this paper, we study a higher-order fractional differential equation with integral boundary conditions and a parameter. Under different conditions of nonlinearity, existence and nonexistence results for positive solutions are derived in terms of different intervals of parameter. Our approach relies on the Guo–Krasnoselskii fixed point theorem on cones

HOW CAN RESEARCH PHARMACEUTICAL COMPANIES BENEFIT FROM STRATEGIC ACTIVATES? An Empirical Study on M&A, Partnership, and R&D Effects

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Parental involvement in online education during Covid-19 lockdown:A netnographic case study of Chinese language teaching in the UK

This paper reports on a study of Chinese parents involvement in their children s heritage language (HL) development during the COVID-19 lockdowns in the UK. Involving seven transnational families, we examined the roles parents played during the online learning sessions and the factors shaping their involvement. Employing a netnographic approach, this study incorporates online classroom observations, semi-structured and focus group interviews with parents, and analysis of their Instagram posts. The study underscores the critical role of parental involvement (PI) in enhancing children s HL education, offering insights into distinct parental roles, including as emotional supporters, co-educators, teaching assistants, and technical supporters. The study introduces a three-dimensional PI model within the framework of family language policy (FLP), enhancing our understanding of FLP by concretely manifesting what, how and why parents get involved in their children s HL development. This study contributes to the discourse on PI and FLP, shedding light on the evolving roles of parents and the complexity of their involvement during the unique circumstances of the pandemic.</p

Blockchain Network Analysis: A Comparative Study of Decentralized Banks

Decentralized finance (DeFi) is known for its unique mechanism design, which applies smart contracts to facilitate peer-to-peer transactions. The decentralized bank is a typical DeFi application. Ideally, a decentralized bank should be decentralized in the transaction. However, many recent studies have found that decentralized banks have not achieved a significant degree of decentralization. This research conducts a comparative study among mainstream decentralized banks. We apply core-periphery network features analysis using the transaction data from four decentralized banks, Liquity, Aave, MakerDao, and Compound. We extract six features and compare the banks' levels of decentralization cross-sectionally. According to the analysis results, we find that: 1) MakerDao and Compound are more decentralized in the transactions than Aave and Liquity. 2) Although decentralized banking transactions are supposed to be decentralized, the data show that four banks have primary external transaction core addresses such as Huobi, Coinbase, Binance, etc. We also discuss four design features that might affect network decentralization. Our research contributes to the literature at the interface of decentralized finance, financial technology (Fintech), and social network analysis and inspires future protocol designs to live up to the promise of decentralized finance for a truly peer-to-peer transaction network

Soil organic pollution and ecological risk assessment in brownfield soil from Northwest China: an integrated analysis of man-land interrelations

In general, chemical plants are accompanied by a variety of secondary production in the production process, which may have different degrees of impact on the environment. At the same time, in order to ensure the environmental safety of new urban construction land, it is necessary to conduct pollution investigation and further environmental risk assessment on potentially polluting abandoned chemical plants. This paper takes a chemical plant producing food grade fumaric acid in Northwest China as an example to investigate the pollution of organic matter in the soil in accordance with relevant standards, then analyzes the vertical pollution degree of key pollution areas. The calculation results of single factor pollution index and Nemerow pollution index show that there are 17 kinds of organic pollutants that exceed the screening value in land of Class I. Among them, benzene, 1,2,3-trichloropropane and 1,1,2,2-tetrachloroethane are most serious, and the highest exceeded the standard by 11,311 times. Moreover, the distillation zone and the reactor zone have reached the level of V pollution, and the maximum pollution depth can reach more than 6 m. The results of HERA software analysis showed that there were 18 and 10 kinds of organic pollutants with carcinogenic risk values exceeding 10−6 in the reactor and distillation area, respectively, and 25 and 11 kinds of organic pollutants with hazard quotients exceeding 1, respectively. According to relevant regulations, the contaminated areas with unacceptable regional risks must be properly repaired