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

Automatically Extracting Information in Medical Dialogue: Expert System And Attention for Labelling

Medical dialogue information extraction is becoming an increasingly significant problem in modern medical care. It is difficult to extract key information from electronic medical records (EMRs) due to their large numbers. Previously, researchers proposed attention-based models for retrieving features from EMRs, but their limitations were reflected in their inability to recognize different categories in medical dialogues. In this paper, we propose a novel model, Expert System and Attention for Labelling (ESAL). We use mixture of experts and pre-trained BERT to retrieve the semantics of different categories, enabling the model to fuse the differences between them. In our experiment, ESAL was applied to a public dataset and the experimental results indicated that ESAL significantly improved the performance of Medical Information Classification

Biomedical Signal Acquisition of Hepatobiliary and Portal Vein Before and After Exercise

In clinical medicine, the research on the hepatobiliary system was proved successfully. In the field of sports medicine, there was little knowledge about the morphological changes, blood distribution, physiological and biochemical as well as pathological changes in the liver, gallbladder and portal vein during exercise. Therefore, studying the function of hepatobiliary system in sports was a problem worthy of attention in sports medicine, and it was also a scientific field that should be urgently studied. Taking exercise-induced abdominal pain as an example, in exercise-induced abdominal pain, the right upper abdominal pain was mainly caused by changes in liver, gallbladder and portal vein. Based on sports medicine, there was little research on the liver, gallbladder and portal vein systems, and the incidence of right upper abdominal pain during exercise was high. The actual mechanism and etiology of the disease still needed to be further confirmed. For this reason, this sports discomfort became the focus of this study. In addition, a safe and effective color Doppler instrument was used to measure the liver and gallbladder and portal vein. The liver, gallbladder and portal vein data before and after exercise were recorded. Based on preliminary experiments and practical results of small samples, it was demonstrated that the liver was ischemic during exercise. It is concluded that this study can lay a foundation for the future research on the liver and biliary portal system, and it is expected to provide safe, non-invasive, reliable, and new indicators for the medical supervision of sports medicine