【Abstract】Integrating natural gas and electricity systems increases system flexibility for the accommodation of the large penetration level of renewable energy and thus achieves decarbonization in the energy system. This paper aims at providing non-iterative and scalable decentralized energy management for multi-integrated natural gas electricity systems with uncertain wind power. An operation space projection transformation method is proposed to reformulate the electricity and natural gas system operation problems for constructing equivalent feasible operation space with the optimality information contained. Accordingly, the proposed decentralized management is privacy-preserving, low-complex, and globally optimal. Moreover, the mathematical proof of the optimality of the reformulated problem is provided. In addition to privacy protection, trust issues are taken into account. Blockchain is applied to safeguard the proposed decentralized management against potential malicious behaviours. We introduce how the proposed decentralized management is embedded in the consensus process of the blockchain. The potential of the projection transformation method in the digital twin application is analyzed. Numerical results are presented to validate the effectiveness of the proposed decentralized energy management method. The synergistic effect and robustness of the proposed operation model are embodied, while the computational accuracy and performance of the non-iterative solution technique are validated.
【Keywords】Integrated energy systems; Coordinated operation; Digital twins; Blockchain; Decentralized management; Operation space projection transformation
【Abstract】The growing importance of the circular economy has emphasised optimal utilisation of resources within the constraints of economic development and protection of the environment. Digital technologies associated with Industry 4.0, such as blockchain, facilitate the implementation of circular economy principles throughout the supply chain. However, because blockchain implementation in the supply chain is still in the early stages, real-world examples of the blockchain-based circular supply chains (CSCs) are limited. The principal purpose of the paper is to examine the critical success factors (CSFs) for implementing blockchain-based CSCs. Following that, 10 CSFs are identified through a short systematic literature review, and then, the integrated fuzzy cognitive mapping and fuzzy best-worst method (FCM-FBWM) is implemented to examine CSFs for the blockchain-based CSC. The study's main findings demonstrate that network collaboration is the best CSF, while the shared circular economy toolbox is counted worst of all. This research enriches the literature by identifying the CSFs for implementing blockchain-enabled CSCs to address the lack of a suitable decision-making framework that assists managers in comprehending how blockchain technology can be adopted in the circular economy context. Implications for theory and practice are also discussed, offering new insights into the measures necessary to ensure successful blockchain implementations in CSCs.
【Abstract】Due to globalization, supply chain networks are moving towards higher complexity and becoming vulnerable to various kinds of attacks such as counterfeiting, information tampering, and so on. Appropriate approaches are necessary to tackle different types of attacks and to ensure the required supply chain security. In this paper, we have addressed the product counterfeiting issue using Physical Unclonable Function (PUF) enabled Radio Frequency Identification (RFID) tag. In this research, as a preferred alternative to the traditional centralized databases, blockchain technology has been leveraged to support anti-counterfeiting. Applying blockchain technology to supply chains can add many useful features such as decentralization, immutability, transparency, traceability, non-repudiation, complicated record-keeping, and so on. We have also used a reputation-based consensus algorithm for the blockchain which is less resource-intensive and thus will not indirectly impose additional cost on supply chain products. In the same research direction, we have devised our system architecture that is suitable for lightweight supply chain devices. The proposed three protocols namely: registration protocol, verification protocol, and transaction protocol along with the blockchain technology help to transfer the ownership of the authentic product and keep the sensitive supply chain information safe. An encryption-based secret sharing technique has also been introduced to assist data protection.
【Abstract】Internet of Things (IoT) systems in different areas, such as manufacturing, transportation, and healthcare, are the convergence of several technologies. There are many concerns about security and privacy drawbacks in IoT systems. Apart from confidentiality supported by encryption primitives, authenticity and non-repudiation are of utmost importance. IoT entities generally use conventional digital signature schemes to achieve imperative goals. However, there are some state-of-the-art digital signatures with more functionalities, IoT-friendly properties, and privacy-preserving features. This survey paper aims to accelerate the adoption of advanced digital signatures. We bridge the gap between the advanced theoretical digital signatures recently designed in cryptographic-oriented papers and the applied IoT systems. It aids researchers in achieving more security, privacy as well as some unique functionality aspects. First, we illustrate the benefits of the hierarchical and heterogeneous IoT architecture supporting the end-edge-fog-cloud continuum accompanying blockchain technology. Second, our survey delves into five state-of-the-art digital signatures, including randomizable, keyless, double-authentication-prevention, sanitizable, and redactable schemes, that are aligned with entities in IoT systems. We provide an outline, taxonomy, comparison table, and diverse IoT-based use cases for each of them. Then, the integration of primitives and the relationship diagrams give guidelines to help select the appropriate advanced digital signatures and highlights how researchers can use them with different IoT entities for preserving privacy and management of trust.
【Abstract】The high energy consumption of cryptocurrency transactions has raised concerns about the environment and sustainability among green investors and regulatory authorities. The current study examines the connectedness among clean energy, Bitcoin, the stock market, and crude oil empirically. The time-varying parameter vector autoregression (TVP-VAR) is used to estimate the dynamics of connectedness in a daily dataset spanning the period November 11, 2013 to September 30, 2021. We find that the clean energy and traditional stock markets transmit shocks to Bitcoin and oil in terms of return, and they receive shocks in terms of volatility from Bitcoin and oil. Additionally, Bitcoin and other financial markets are only tenuously linked during non-crisis periods. Nonetheless, their connection strengthens substantially during times of crisis, such as the great cryptocurrency crash of 2018 and the COVID-19 pandemic of 2020. We believe that these findings can help explain how clean energy and cryptocurrency markets are linked during times of crisis.
【Abstract】Purpose This study aims to conduct performance and clustering analyses with the help of Digital Government Reference Library (DGRL) v16.6 database examining the role of emerging technologies (ETs) in public services delivery. Design/methodology/approach VOSviewer and SciMAT techniques were used for clustering and mapping the use of ETs in the public services delivery. Collecting documents from the DGRL v16.6 database, the paper uses text mining analysis for identifying key terms and trends in e-Government research regarding ETs and public services. Findings The analysis indicates that all ETs are strongly linked to each other, except for blockchain technologies (due to its disruptive nature), which indicate that ETs can be, therefore, seen as accumulative knowledge. In addition, on the whole, findings identify four stages in the evolution of ETs and their application to public services: the "electronic administration" stage, the "technological baseline" stage, the "managerial" stage and the "disruptive technological" stage. Practical implications The output of the present research will help to orient policymakers in the implementation and use of ETs, evaluating the influence of these technologies on public services. Social implications The research helps researchers to track research trends and uncover new paths on ETs and its implementation in public services. Originality/value Recent research has focused on the need of implementing ETs for improving public services, which could help cities to improve the citizens' quality of life in urban areas. This paper contributes to expanding the knowledge about ETs and its implementation in public services, identifying trends and networks in the research about these issues.
【Abstract】Legal requirements and consumer demands have motivated the development and application of traceability technology. Farming practices are the starting point of the agri-food supply chain and the destination of the agri-food traceability system (AFTS). The amount of resource information and the complexity of the production process of agri-food become the main obstacles to the wide application of AFTS. This study introduces an integrated machine-to-machine system that allows collecting field operation information automatically. This system includes an IoT-based integrated hardware system, a smart farm cloud (SFC) platform, and a mobile application, which accomplished the collection, upload, and storage of operation information. This system had been used in "BSD" organic apple orchard in Qixia, Shandong Province, China for about one year. The effectiveness of the system was evaluated by managing 270 apple trees in one plot of the orchard. Finally, a label with a QR code was successfully generated to provide consumers to query traceability information from a single tree to a fruit tray. This work was a background of a blockchain traceability system. Moreover, the future extendibility of the system was also discussed and prospected.
【Abstract】The paper examines the influence of investor sentiment based on news headlines on the Cryptocurrency Market Index and ten individual cryptocurrency returns. We capture investors' sentiment from cryptocurrency-specific news headlines. We use a lexicon-based Natural Language Processing (NLP) technique to construct a unique sentiment indicator, and the sentiment scores are generated using two financial dictionaries: Henry(2008)(HE) and Loughran and Mcdonald(2011)(LM). The findings of the study show that news sentiment has a significant impact on cryptocurrency returns. When the investors' sentiment is optimistic or bullish, the cryptocurrency market experiences herding behaviour, leading to an increase in prices. The diverse and heterogeneous nature of the various cryptocurrencies causes each individual cryptocurrency to respond differently to sentiment. Further, we see that sentiment has a more pronounced impact on young, small, and volatile cryptocurrencies. Our study is among the few studies that use cryptocurrency-specific news headlines rather than news bodies to build a news sentiment indicator. JEL codes: E49, G14, G15
【Abstract】The Electronic Medical Record (EMR) is a valuable source of medical data intelligence in e-health systems. The watermarking techniques have been used to authenticate the owner and protect the EMR from illegal copying. The existing distributive strategies, successfully operated to secure the EMR, are found to be inadequate. Blockchain technology, mainly, is employed by a sharing database that allows the digital crypto-currency. It rapidly leads to the magnified expectations acme. In this excitement, the use of consortium adopting the technology based on Blockchain, in the EMR structure, is found improving. This type of consortium adds an immutable share with a translucent record of the entire business and it is accomplished with responsibility, along with faith and transparency. The combination of watermarking and Blockchain technology provides a singular chance to promote a secured, trustworthy electronic documents administration to share with the e-records system. The authors, in this article, present their views on consortium Blockchain technology which is incorporated in the EMR system. The ledger, used for the distribution of the block structure, has team healthcare models based on dissimilar multiple image watermarking techniques.
【Abstract】Cryptoassets such as Bitcoin and Ethereum are widely traded around the world. Cryptocurrencies are also transferred between investors. Cryptocurrency has become a new and attractive means of remittance. Thus, blockchain-based smart contracts also attract attention when central banks design digital currencies. However, it has been discovered that a significant amount of cryptoassets on blockchain are lost or stranded for a variety of reasons, including the loss of the private key or the owner's death. To address this issue, we propose a method for recoverable transactions that would replace the traditional transaction by allowing cryptoassets to be sent to a backup account address after a deadline has passed. We provide the computational workload required for our method by analyzing the prototype. The method proposed in this paper can be considered as a good model for digital currency design, including central bank digital currency (CBDC).
【Abstract】Purpose This paper aims to analyse COVID-19 indices and blockchain features on Bitcoin and Ethereum returns, respectively. The authors focus on the most used and owned cryptocurrencies that cover Europe, the US and Asian countries. Design/methodology/approach An autoregressive distributed lag panel (pooled mean group and mean group) is utilized, and a robustness check is incorporated by using a Random Effect Model and Generalized Method of Moments (GMM). Findings Four new findings were discovered, including (1) the vaccine confidence index (VCI) pushes economic recovery and increased demand for the Bitcoin market, but the opposite result was interestingly observed from Ethereum; (2) the blockchain features were revealed to be essential to Bitcoin, while they were irrelevant to Ethereum for short-run country-specific results; (3) the hash rate and network difficulty moved inversely during the pandemic; and (4) the government played a significant role in taking action during uncertain times and regarding cryptocurrency policies. Research limitations/implications VCI is constructed by the most used vaccine type in our sample countries (i.e. Pfizer), as the data for a specific classification by each type is still unavailable. Practical implications Providing an evenly distributed vaccination program primary vaccination series against COVID-19 to the citizens is an essential duty of the government. Bitcoin policymakers and investors should watch the COVID-19 vaccine distributions closely as it will affect its return. Ethereum is emphasized to keep developing its smart contract which appeared to outplay other blockchain features. Cryptocurrency investors should be wise in their investment decisions by analysing the news thoroughly. Social implications This research emphasizes that the success in the roll-out of COVID-19 vaccination requires citizens' willingness to participate and their trust in the vaccine's efficacy. Such self-awareness and self-discipline in society can ultimately empower individuals and stabilise the economy. Nevertheless, the implementation of health protocols is still highly required to prevent the spread of new variants of COVID-19. Originality/value This is the first study that attempts to construct a VCI which denotes the confidence derived from the administration of full-dose COVID-19 vaccines (an initial vaccine and a second vaccine). The authors further find the impact on cryptocurrency returns. Next, blockchain size is utilized as a new determinant of cryptocurrencies.
【Abstract】In its modern form, electronic money is divided into two main categories: card-type electronic money and software-type electronic money. Electronic money originated and from the beginning became widespread as card-type money. The term "electronic money" itself referred to the amounts that were displayed on the chips of cards of traditional payment systems. The sequence of stages of the development of electronic money begins its development with records in the computer memory of banks, which were reprinted from paper media. In the last century, digital money and electronic wallets emerged with the help of electronic pulses, which were endowed with the right of a means of payment.
【Abstract】Many countries and governments consider smart cities a solution to global warming, population growth, and resource depletion. Numerous challenges arise while creating a smart city. Digital twins, along with the Internet of Things, fifth-generation wireless systems, blockchain, collaborative computing, simulation, and artificial intelligence technologies, offer great potential in the transformation of the current urban governance paradigm toward smart cities. In this paper, the concept of a digital twin city (DTC) is proposed. The characteristics, key technologies, and application scenarios of a DTC are elaborated upon. Further, we discuss the theories, research directions, and framework regarding DTCs. (c) 2021 China Science Publishing & Media Ltd. Publishing Services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
