Research on Architecture of Risk Assessment System Based on Block Chain

The risk assessment system has been applied to the information security,energy,medical and other industries.Through the risk assessment system,it is possible to quantify the possibility of the impact or loss caused by an event before or after an event,thereby avoiding the risk or reducing the loss.However,the existing risk assessment system architecture is mostly a centralized architecture,which could lead to problems such as data leakage,tampering,and central cheating.Combined with the technology of block chain,which has the characteristics of decentralization,security and credibility,collective maintenance,and untamperability.This paper proposes a new block chainbased risk assessment system architecture and a consensus mechanism algorithm based on DPOS improvement.This architecture uses an improved consensus mechanism to achieve a safe and efficient risk assessment solving the problem of data tampering in the risk assessment process,avoiding data leakage caused by improper data storage.A convenient,safe and fast risk assessment is achieved in conjunction with the improved consensus mechanism.In addition,by comparing existing risk assessment architecture,the advantages and impacts of the new block chain-based risk assessment system architecture are analyzed.

Research on Application of Supply Chain Finance Based on Block Chain

Supply chain finance has played a positive role in solving the financing difficulties of small and medium-sized enterprises.However,in the actual implementation process,there are still problems such as information asymmetry,doubts about the authenticity of trade background,and high operational risks,which seriously restrict the development of supply chain finance.However,block chain technology has the characteristics of de-centralization,data transparency,common maintenance and non-tampering.Applying this technology to supply chain finance can effectively solve the existing problems.Based on the research on the development status of traditional supply chain finance,this paper puts forward a new development mode of supply chain finance based on block chain technology,and through the analysis of typical cases,finally gives some policy suggestions for the development of block chain supply chain finance.

The Construction of Drug Traceability System Based on Block Chain Technology

Objective To analyze the current problems in drug traceability and supply chain management,and build the drug traceability system based on the block chain technology so as to provide authenticity assurance for the real data in the whole life cycle of drugs.Methods A new drug regulatory traceability protocol was designed based on block chain technology.The database of drug production,circulation and use was linked closely.A traceability system was set up according to the traceability protocol,and the consensus complexity and safety performance of the system were analyzed.Results and Conclusion The distributed account book and tamper-proof functions of the block chain platform were used to establish a double-chain system based on the combination of public chain and private chain,which could make the data of drugs more reliable,transparent and traceable with good application value.The establishment of a double-chain traceability system is studied so that drug market license holders,manufacturers,operating enterprises and users can verify the data to form an interconnected drug traceability data chain.

Path of the Information Asymmetry of Asset Backed Securitization—Information Game Analysis of Embedded Block Chain Technology

In recent years, the rapid innovation and development of financial industry has made financial enterprises have a lot of information. However, the large amount of information is tampered with and fragmented, which cannot be shared. With the constant innovation of science and technology, it is the most effective way to solve the information lag and asymmetry of financial products. This article aims to start from the problem of asymmetric information of financial products, the analysis of the emerging block chain technology applied in the financial sector, and with the development of asset securitization information known as the typical scenario for the first time, a concrete analysis information game process, and discuss about the application of chain blocks in securitization feasibility.

Integration of Fog Computing for Health Record Management Using Blockchain Technology

Internet of Medical Things (IoMT) is a breakthrough technologyin the transfer of medical data via a communication system. Wearable sensordevices collect patient data and transfer them through mobile internet, thatis, the IoMT. Recently, the shift in paradigm from manual data storage toelectronic health recording on fog, edge, and cloud computing has been noted.These advanced computing technologies have facilitated medical services withminimum cost and available conditions. However, the IoMT raises a highconcern on network security and patient data privacy in the health caresystem. The main issue is the transmission of health data with high security inthe fog computing model. In today’s market, the best solution is blockchaintechnology. This technology provides high-end security and authenticationin storing and transferring data. In this research, a blockchain-based fogcomputing model is proposed for the IoMT. The proposed technique embedsa block chain with the yet another consensus (YAC) protocol building securityinfrastructure into fog computing for storing and transferring IoMT data inthe network. YAC is a consensus protocol that authenticates the input datain the block chain. In this scenario, the patients and their family membersare allowed to access the data. The empirical outcome of the proposedtechnique indicates high reliability and security against dangerous threats.The major advantages of using the blockchain model are high transparency,good traceability, and high processing speed. The technique also exhibitshigh reliability and efficiency in accessing data with secure transmission. Theproposed technique achieves 95% reliability in transferring a large number offiles up to 10,000.

Blockchain Challenges in Maritime Industry: An Empirical Investigation of the Willingness and the Main Drivers of Adoption from the Hellenic Shipping Industry

In the shipping industry, significant part of the documents exchange still have the traditional paper form, mainly due to security concerns, despite the size and modernization efforts of this market. We explore the adoption of the blockchain and Distributed Ledger Technologies to address document exchange in a fast and secure way.

An Association Ring Signature for Block Chain E-Money Transactions

Block chain is widely used in the financial field for its characteristics of decentralization, anonymity and trust. Electronic money payment is an important application hotspot. Ring signature is widely used in strong anonymous authentication such as electronic cash and electronic voting because of its unconditional anonymity, spontaneity and flexible group structure. Among them, the correlation ring signature can prove whether two signatures are issued by the same person without revealing the identity of the real signer. Therefore, the signature right breach can be avoided based on the premise of guaranteeing anonymity, such as repeated voting, electronic money repetition cost and so on. Most of the existing correlation ring signature security is based on the discrete logarithm problem, and most of the schemes result in the degradation of anonymity because of strong association. These methods do not apply to the block chain electronic currency transaction scene with strong anonymity. Therefore, this paper first proposes a blockchain-based electronic currency transaction security model. The model ensures not only the anonymity of both parties but also a certain degree of traceability. In order to support these two characteristics, this paper proposes an association ring signature method based on large integer decomposition problem. This method has strong anonymity and can be applied to blockchain scenes. On the other hand, it can be converted into group signatures in specific scenarios. It is therefore traceable. Finally, the adaptive selection message of the scheme and the unforgeability under the selection of public key attack are proved under the random oracle model.

A COMPARATIVE STUDY OF CHAIN DYNAMICS OF DI-AND TRI-BLOCK COPOLYMERS IN SEMIDILUTE SOLUTION IN A NON-SELECTIVE SOLVENT

The chain dynamics of a pair of diblock poly(styrene-b-butadiene) (PS210-b-PB960) and triblock poly(styrene-b-butadiene-b-styrene) (PS200-b-PB1815-b-PS200) copolymers in both dilute and semidilute toluene solutions has been comparatively studied by dynamic laser light scattering. As expected, the mutual diffusion of individual chain changes into a fast cooperative diffusion of the chain segments ('blobs') between two neighboring entanglement points for both the copolymers as the solution changes from dilute to semidilute. Further increases of the concentration lead to a second slow relaxation mode. For the triblock chains, there exists an additional middle relaxation between the fast and the slow modes. The concentration (c) dependent study of the average characteristic decay time of the fast mode ((tau(f))) reveals that 1/(tau(f)) - c(-a) with 0.33 < alpha < 0.44, much smaller than 0.75 predicted or 0.72 observed for linear homopolymer chains in good solvent. It implies that the solvent quality of toluene for PB might not be as good as that for PS. Due to such a difference in solubility, it is reasonable to speculate that the PB and PS blocks are transiently segregated in semidilute solution. The relaxation of these transient PB and PS richer domains leads to the observed slow relaxation. Such a speculation is supported by the appearance of an additional slow relaxation mode in the study of polyisoprene-b-polystyrene-b-polyisoprene in semidilute solution in cyclohexane, a non-selective solvent, in which we alternated the solubility difference by a variation of the solution temperature.

元宇宙:概念、技术及应用研究综述

网络技术、人机交互和人工智能等技术的飞速发展催生了元宇宙,并进一步促进人们物质生活各个方面的数字化转型.2021年是元宇宙元年,元宇宙作为一个新兴的概念受到产业界、学术界、媒体界及公众的广泛关注.本文尝试从技术维度和应用角度深度剖析元宇宙.首先,从定义、起源与发展、特征和关键技术(网络及运算技术、物联网技术、人机交互技术、电子游戏技术、区块链技术、数字孪生技术和其他技术)等多方面对元宇宙的概念及内涵进行论述;然后,讨论了当下布局元宇宙的企业和应用实例;最后,剖析了目前元宇宙发展存在的问题和机遇,并对未来研究与应用进行了展望.通过对元宇宙当前的发展状况、研究趋势进行归纳分析以及科学地评估元宇宙的落地应用,为元宇宙研究人员提供有益的参考和借鉴.

基于blockchain技术的数据交易方式设计

伴随着大数据时代的来临,数据交易的兴起是大势所趋。但当前交易模式的诸多不足影响了数据交易产业的发展,如:交易平台对数据的托管、交易双方隐私性难以保证、数据所有权证明困难、小型数据拥有者没有交易渠道以及数据质量的参差不去。基于区块链技术,设计新型数据交易平台,消除数据交易产业发展的阻碍。

基于迭代协作学习框架的信誉医学参与方选择

联邦学习和群智学习等协作学习技术,能够在保护数据隐私的条件下充分利用分布在各地的分布式数据深度挖掘数据中所蕴含的知识,拥有非常广阔的应用前景,尤其是在强调隐私惯例和道德约束的医疗健康领域.任何协作工作都需要选择可靠的参与方,协作学习中全局模型的性能在很大程度上取决于参与方的选择.然而,现有研究在选择参与方时都没有对不同机构医疗数据中存在的异质性加以直接关注.导致包含稳定性在内的全局模型的性能难以得到保障.提出了从信誉的角度尝试探索求解该问题.以迭代协作学习的方式尽可能挑选出具有良好信誉的参与方进行协作学习,以获得稳定可靠的高性能全局模型.首先,提出了一个描述医疗机构数据质量的AI信誉值指标AMP(AI medical promise),以帮助其在医疗领域中形成良好的AI生态.其次,建立了一个基于后向选择的迭代协作学习(colback-learning)框架.在单次协作学习任务中,利用后向选择方法以多项式时间复杂度迭代计算出性能良好且稳定的全局模型,完成AMP计算和积累.在AMP信誉值计算中,制定了一个综合考虑全局性能指标的评分函数,以针对医疗领域更有效地指导全局模型的训练.最后,使用真实医疗数据模拟多样化的协作学习场景.实验表明,colback-learning能够选择可靠参与方训练得到性能良好的全局模型,模型的性能稳定性比现有最好的参与方选择方法提高了1.3~6倍.全局模型的可解释性与集中式学习保持了较高的一致性.

基于区块链的医联体护理协同管理系统的设计与实现

目的:设计一种基于区块链的医联体护理协同管理系统,为实现医联体护理协同管理提供技术支持。方法:该系统基于联盟链的5层技术架构进行设计,通过Linux系统搭建Fabric开发环境及网络配置,采用智能合约和Java语言软件开发工具包实现用户界面操作,使用Bootstrap和Jquery等技术搭建前端Web界面、Spring Boot搭建系统后端,并通过加密算法、哈希运算、智能合约、共识机制等技术实现联盟链成员管理、业务管理、数据存储与共享、患者病历管理及平台监管5个功能模块。结果:该系统完善了优质护理资源下沉与连续性护理机制,重构了积分激励机制,促进了护理共生网络协同进化,并使多节点交互,形成了协同合力。结论:该系统顺应全新模式下医联体整合型护理服务的发展趋势,对提升护理核心竞争力等方面起到重要推动作用,同时为构建适用于医联体场景的区块链方案提供了借鉴。

数字贸易背景下区块链电子提单的应用研究

随着数字贸易的不断推进,传统海运提单在实务中的缺陷更加突出。电子提单不仅能够有效解决近洋运输及远洋运输中特殊情境下因“货等单”引致的无单放货问题,更能迎合数字贸易发展的时代需求。电子提单已问世多年,但因受到数字技术、运营环境及法律法规等因素的影响至今尚未得到广泛应用。文章从电子提单发展历程切入,分析了区块链电子提单系统的逻辑框架及电子提单的生成与流转机理,剖析了区块链电子提单应用中亟待解决的几个问题,进而提出电子提单普及应用的策略建议。

基于区块链模式的政务主数据治理机制模型研究

阐述了政务主数据在政府不同部门和系统之间业务协同、共享需求中的重要性,分析了大数据网络中各节点政务主数据一致性和安全性的保障问题,提出了基于区块链模式的政务主数据治理机制。通过运用信息规划研究方法,分析了3种经典的数据治理模式,进而提出一种新的治理机制,旨在解决数据运用过程中政务主数据一致性得不到保障和隐私安全受到威胁的问题。该机制利用区块链技术的价值,将区块链的思维方式嵌入政务主数据治理结构中,以赋能政务主数据一致性治理的全过程,从而提高数据质量和业务办理的专业性,实现政务主数据价值的最大化。

元宇宙技术近期发展动态

元宇宙是一种能够映射现实世界并且可深度交互的虚拟环境,在诸多应用领域具备技术引领性。对近期元宇宙技术领域的主要发展动向进行了综合评述。首先介绍元宇宙技术的最新进展,随后分析元宇宙技术的军事应用进展和挑战,最后概述元宇宙技术的未来发展趋势。综述表明,扩展现实、数字孪生、区块链、“人-机”交互控制等元宇宙核心技术,近来研发进展明显、应用加速;元宇宙技术对军事训练、作战指挥控制、战场数据融合处理等任务均有较好的改进前景,但是目前依然面临数据流通不畅、生理舒适度不佳、信息安全隐患加剧、监督立法进程滞后等发展挑战。综述认为,强化数据互通和互操作能力、提升人机交互的友好性和便捷性、保障信息安全和保护措施、完善伦理和法律监管能力等,正在成为未来元宇宙技术的重要发展方向。

崩塌滑坡-堰塞湖-溃决洪水-泥石流灾害链演化特征分析及防治对策研究

某沟谷两岸坡面陡峻,沟谷狭窄,纵坡降较大,在地震、降雨等不利因素影响下,其左岸堆积体上方的崩滑堵沟隐患点可能出现失稳,并发展为崩塌滑坡-堰塞湖-溃决洪水-泥石流灾害链。针对此灾害链不同阶段的演化特征,采用相应的数值模拟模型和数值计算方法进行模拟分析和计算,评价其对沟口桥梁工程的影响,并采取相应的防治对策。经分析计算,崩塌滑坡隐患点距沟底高程落差约1 km,岩体体积约8×10^(6)m^(3),平均厚度约26 m,崩塌滑坡堵河可形成最大水深为14.4 m、面积约为7.19×10^(4)m^(2)、方量约为2.74×10^(5)m^(3)的堰塞湖;堰塞湖溃决形成洪水过程中,桥梁处最大水深为4.43 m(不含原始水位),最大流速为7.54 m/s,峰值流量为807 m^(3)/s;在溃决洪水强烈揭底冲刷和侵蚀的条件下,溃决洪水引发的泥石流在桥梁处的最大水深为7.1 m、最大流速为8 m/s、峰值流量为1685.5 m^(3)/s、最大冲刷深度为16.58 m。为减少该灾害链对桥梁工程的影响,采取河道疏通、岸坡防护和监测预警等防治措施。

区块链在分布式能源交易的应用架构及安全性分析

随着电力工业发展,电能逐渐还原商品属性。电力交易模式由集中式向分布式逐渐演化,引发市场主体互信不足、数据安全性不高、管理难度大等隐患。文章分析了区块链技术在电力交易市场中的应用模式。从定量分析了角度评估电力交易区块链信息安全性。结合区块链技术特征与电力交易通信机制,建立抗毁性与生存度指标,建模定量分析了“弱中心化”电力交易区块链通信网络安全性。算例分析结果表明,“弱中心化”分布式电力交易通信架构相比传统的中心化“星型”通信架构,在可靠度取值范围为0.90~0.99时,前者实际抗毁性比后者提高了2.67%~31.07%,前者实际生存度比后者提高了5.31~5.95倍。

基于多链的果蔬全程全息信息管理模型构建与系统化实现

果蔬全供应链既具有业务环节繁杂、数据多源异构、利益角色众多等通用食品供应链特征,又具有风险演变趋势复杂、时效性要求强、存在突发新发风险等特性。为有效解决传统果蔬供应链监管方案存在的监管覆盖面不足、溯源效应周期长、各主体间协同效应差等问题,构建了基于区块链多链的果蔬全程全息信息管理模型,并进行了系统化验收。首先,在果蔬全程全息信息解析的基础上,构建基于多链的果蔬全程全息信息管理模型。然后,提出一种基于区块综合索引指数的果蔬信息快速检索方法,并设计了基于公证链的果蔬信息跨链安全交互机制。其次,基于长安链开源区块链平台设计并开发了果蔬全程全息信息管理原型系统。最后,进行了实验验证和系统案例应用分析。结果表明,本系统公开数据上链平均耗时为589.03ms,隐私数据上链平均耗时为708.59ms,公开数据查询平均耗时为26.87ms,隐私数据查询平均耗时为30.67ms。本文设计的基于多链的果蔬全程全息信息管理模型及系统在满足不同需求用户对于不同权限信息的上链和查询需求的同时,实现了对果蔬全程全息信息的穿透式监管,满足了企业对隐私数据的权限控制与安全共享需求,提高了果蔬信息检索效率,为果蔬全程全息信息管理模型开发提供参考与借鉴。

DEALS——追踪代币转账信息不一致

区块链使传统的交易所和借贷机构能够扩展到去中心化平台(decentralized platform,Depl),任何人都可以在没有中介机构帮助的情况下进行交易和借贷.大多数Depl都是作为运行在以太坊上的智能合约实现的,并与另一种智能合约、加密货币(即代币)交互,以实现各种功能.尽管Depl涉及价值超过350亿的美元,但人们对代币的实际转移是否如Depl预期的那样一致知之甚少.代币的实际转移与Depl期望的不一致被称为行为不一致,这种不一致的出现将导致财产的损失和用户的质疑.在这项工作中,我们迈出了调查Depl和代币之间的这种不一致的第一步.我们提出通过监控Depl和代币的核心数据结构变化,将实际的代币转移行为与Depl内部记录指示的行为进行比较,自动检测不一致.实验结果表明,在1 012 749笔交易中存在不一致行为,涉及2 871对Depl和代币,与110个Depl和2 544个代币相关.实验结果的精准度为98.0%.此外,还总结了导致不一致的10大原因,例如诈骗Depl、Depl与代币尺度不一致、锁币规则不明确等.

基于联盟链的边缘缓存系统中最佳缓存策略设计

针对不同运营商各自部署边缘设备,投入巨大且缓存内容相互隔离,无法共享的问题,改进了一种基于联盟链的边缘缓存系统架构,使运营商部署的边缘设备间能够打破内容隔离,实现更大范围的共享。为了提高运营商缓存收益,同时保证用户传输质量,降低用户传输时延,首先针对缓存内容流行度、内容大小以及边缘设备的协作能力,分析不同内容交付方式对于用户传输时延和运营商缓存收益的影响;然后,以最大化缓存收益和最小化传输时延为目标建立优化问题;最后,为解决构建的高维度大规模的缓存决策问题,采用基于异步优势动作评价的内容缓存算法确定内容的最佳放置位置。仿真结果表明,所提缓存策略能够有效地提高边缘缓存收益,降低内容传输时延,提升用户体验。