【Abstract】The concept of the metaverse was first coined in the science fiction novel Snow Crash published 30 years ago, serving as the pregenesis concept of the next groundbreaking development in communication and technology fields for several decades. Today, the concept of the metaverse is complicated and often discussed as a multidimensional notion, generally referring to multiple interconnected virtual worlds where large numbers of users can simultaneously interact in embodied form. In this article, we propose the bifold triadic relationships model to help advertising scholars understand how advertising may work in the metaverse and to guide future research endeavors. Although the metaverse as a concept has yet to fully form, we hope that this primer presents a clearer layout of how advertising can be studied at the unit level of triadic relationships among consumer, media, and engagement behaviors in the metaverse space. Using what we know thus far about immersive virtual environments and how they relate to advertising practice and scholarship, the present article serves as an impetus for new directions in advertising theory and research in the metaverse in the years to come.
【Abstract】Purpose This paper reports exploratory findings about teaching in the metaverse using a virtual reality (VR) platform and head-mounted displays. This paper addresses three research questions: Is the metaverse an appropriate platform for teaching Lean? What are the benefits and problems of this approach over traditional classroom methods? What are the future implications for teaching Lean in the VR-enabled metaverse? Design/methodology/approach The research presented in this paper is exploratory. A critical realism approach is adopted using action research through the preparation, delivery and review of the first four masterclasses entitled Leading Intelligent Lean offered by Gemba (formerly The Leadership Network). The data collection methods included a pre-workshop questionnaire, participant observation, focus groups and end-of-course surveys. Findings It was found that Lean can be taught successfully in the metaverse. There are many related benefits, particularly in terms of the high levels of immersion and the "wow" factor. Remaining technological limitations are reduced by continually improving the metaverse platform and the course content and delivery. The authors conclude that the metaverse is a useful addition to teaching Lean - and is especially promising when used in a blended teaching approach. Originality/value To the best of the authors' knowledge, this is the first report of teaching Lean in a VR-enabled metaverse and one of the first of teaching and learning in the metaverse regardless of topic. The respective problems and benefits of this approach versus teaching in a traditional classroom setting are discussed.
【Abstract】2021 is known as the first Year of the Metaverse, and around the world, internet giants are eager to devote themselves to it. In this review, we will introduce the concept, current development, and application of the Metaverse and the use of the current basic technologies in the medical field, such as virtual reality and telemedicine. We also probe into the new model of gastroenterology in the future era of the Metaverse.
【Abstract】The recent 50% drop in the price of the flagship cryptocurrency Bitcoin reinforces the persistent anxiety among cryptocurrency investors. Can alternative assets hedge Bitcoin risk? This study investigates the ability of equities, commodities, bonds, currencies, and VIX futures to hedge Bitcoin. Our in-sample analysis shows that the USDX, Gilt, Australian dollars, wheat, cocoa, cotton, sugar, copper, and lean hog can hedge Bitcoin, and the out-of-sample analysis reveals that the DAX, Dow-Jones, Nikkei, S&P 500, Brent, and WTI futures can be effective hedging instruments. We use a wavelet-based dynamic hedging model to account for heterogeneous investors in the Bitcoin market. For a short-term horizon, soybean futures reduce the variance in the in-sample hedged portfolio, and cotton futures offer the highest out-of-sample utility. Copper futures are the best for in-sample hedging in a long-term horizon, whereas live cattle futures have the best out-of-sample performance. These results show that conventional assets can hedge wild swings in Bitcoin. Copyright (C) 2021, Borsa Istanbul Anonim Sirketi. Published by Elsevier B.V.
【Abstract】The traditional Industrial Internet-of-Things (IIoT) ecosystem utilizes the Trusted Third Party (TTP) to store sensitive data, and TTP acts as a middleware for device authentication. Therefore, maintaining data privacy is one of the main challenges and research issues due to third-party involvement. Moreover, several known challenges such as Single-Point-of-Failure (SPoF), trust issues, centralized systems, and security vulnerabilities exist in the IIoT ecosystem. Blockchain is one of the solutions to address above mentioned challenges. This article proposes a fully decentralized system (without TTP) based on the ethereum smart contracts and Interplanetary File System (IPFS) for IIoT. Moreover, we propose a device authentication mechanism by utilizing smart contracts and storing the data in a distributed manner using IPFS. This work also provides data accessing policies for the end-users. The proposed contract is implemented in both JavaScript VM and ropsten test networks. It provides an in-depth analysis of the smart contract while simulating the contract in local and global environments. Moreover, the various costs involved in proposing the protocol are also calculated and compared to current studies. The informal investigation demonstrates that the solutions are secure and meet critical security criteria.
【Abstract】Over the last decade, Bitcoin has revolutionized the global economic and technological landscape, inspiring a new generation of blockchain-based technologies. Its protocol is today among the most influential for cryptocurrencies and distributed networks. In particular, the P2P layer represents a reference point for all permissionless blockchains, which often implement its solutions in their network layer. Unfortunately, the Bitcoin network protocol lacks a strong security model, leaving it exposed to several threats. Attacks at this level can affect the reliability and trustworthiness of the consensus layer, mining the credibility of the whole system. It is therefore of utmost importance to properly understand and address the security of the Bitcoin P2P protocol. In this paper, we give a comprehensive and detailed overview of known network-level attacks in Bitcoin, as well as the countermeasures that have been implemented in the protocol. We propose a generic network adversary model, and propose an objective-based taxonomy of the attacks. Finally, we identify the core weaknesses of the protocol and study the relationship between different types of attack. We believe our contribution can help both new and experienced researchers have a broader and deeper understanding of the Bitcoin P2P network and its threats, and allow for a better modeling of its security properties.
【Abstract】In this paper, a blockchain-based framework involving a traceability system for product recall (TSPR) is proposed to develop a traceability system integrated into the product recall system deployed to the Ethereum to ensure the transparency and visibility of the recall process for all stakeholders. The proposed system incorporates all four stakeholders, including supply chain (SC) participants, the food safety regulatory system, the admin, and end customers, into one chain. In the proposed TSPR system, individual components are developed to provide primarily product traceability events, product recall data and status, which are stored in the blockchain to authorized stakeholders. Moreover, the entity relationship and activity diagram of the TSPR system are developed. In the experiment, three smart contracts of the TSPR system are developed using Remix IDE running on an Ethereum test network. A scenario of the events of product traceability and recall in the SC is developed. Two criteria are used to test the validation of contracts: the correct operation and measurement of gas costs. The results show the correctness of three smart contracts, thereby ensuring that the stakeholder chain is provided with visibility and transparency primarily for the product recall process. Moreover, the summation of gas costs deployed in the TSPR system in Ethereum Mainnet for the regulator and manufacturer is $30.23 and $111.54, respectively. However, when using the Polygon Ethereum Virtual Machine (EVM), the gas cost remains $0.022 and $0.083, respectively; thus, this system for stakeholders may help them to achieve lower costs and increased economic worth.
【Abstract】Bitcoin has made an increasing impact on the world's economy and financial order, which attracted extensive attention of researchers and regulators from all over the world. Most previous studies had focused more on the transaction layer, but less on the network layer. In this paper, we developed BNS(Bitcoin Network Sniffer), which could find and connect nodes in the Bitcoin network, and made a measurement in detail. We collected nearly 4.1 million nodes in 1.5 hours and identified 9,515 reachable nodes. We counted the reachable nodes' properties such as: service type, port number, client version and geographic distribution. In addition, we analyzed the stability of the reachable nodes in depth and found nearly 60% kept stable during 15 days. Finally, we proposed a new approach to infer the Bitcoin network topology by analyzing the Neighbor Addresses of Adjacent Nodes and their timestamps, which had an accuracy over 80%.
【Abstract】Smart contracts are widely employed in many industries as a result of the high-quality development of science and economic technology, as well as the introduction of blockchain, which can automatically conduct retrieval, verification, and payment tasks. Smart contracts as an emerging topic, particularly the study of smart legal contracts, must remain forward-looking, and the smart contract sector cannot wait for the legal status of smart contracts to be resolved before advancing. The relative lag of the law becomes unavoidable due to the unassembled and unpredictable character of the law and thus its legislation. In this paper, we explore the incorporation of smart contracts into the scope of legal regulation, the construction of a series of systems for smart contracts, and the prognosis of smart contracts in terms of contract logic, arbitration process, and formal verification from the current law. Furthermore, a smart contract payment template based on semantic-aware graph neural networks is proposed to address the traditional smart contract vulnerability detection payment template method's low detection accuracy and high false alarm rate, as well as the neural network-based method's insufficient mining of bytecode-level smart contract features. Experiments comparing the method described in this research to comparable methods reveal that the strategy proposed in this study improves all types of indicators significantly.
【Abstract】During the COVID-19 pandemic, cryptocurrency prices showed abnormal volatility that attracted the participation of many investors. Studying the behaviour of volatility for the prices of cryptocurrency is an interesting problem to be investigated. This research implements the state space model framework for volatility incorporating the Kalman filter. This method directly forecasts the conditional volatility of five cryptocurrency prices (Bitcoin (BTC), Ethereum (ETH), Ripple (XRP), Litecoin (LTC) and Bitcoin Cash (BCH)) for 10,000 consecutive hours, i.e., approximately 417 days during the COVID-19 pandemic from 26 February 2020, 00:00 h until 18 April 2021, 00:00 h. The performance of this model is compared to the GARCH (1,1) model and the neural network autoregressive (NNAR) based on root mean square error (RMSE), mean absolute error (MAE) and the volatility plot. The autocorrelation function plot, histogram and the residuals plot are used to examine the model adequacy. Among the three models, the state space model gives the best fit. The state space model gives the narrowest confidence interval of volatility and value-at-risk forecasts among the three models.
【Abstract】In view of the current chaotic structure of smart contracts and no unified definition of smart contracts, the implementation of smart contracts for the same business in the same field is quite different due to different development institutions and operating platforms, resulting in a low level of smart contract sharing and high development costs, hindering the development of smart contracts. Combined with the intellectual property transaction scenario, this paper proposes a blockchain-based intellectual property transaction smart contract form specification, designs the overall structure and process specification of the smart contract in the intellectual property transaction process, formulates a standard for the standardization of smart contract writing in intellectual property transaction scenarios, and solves the current chaotic structure of intellectual property transaction smart contracts, which is conducive to the collaborative development of scholars in various fields.
【Abstract】Stablecoins and central bank digital currencies are on the horizon in Asia, and in some cases have already arrived. This paper provides new analysis and a critique of the use case for both forms of digital currency. It provides time-varying estimates of devaluation risk for the leading stablecoin, Tether, using data from the futures market. It describes the formidable obstacles to widespread use of central bank digital currencies in cross-border transactions, the context in which their utility is arguably greatest. The bottom line is that significant uncertainties continue to dog the region's digital currency initiatives.
【Abstract】Introduction: Youngsters are the segment that dedicates the most time to the online entertainment and thus, brands that realize this behavior, use the videogames like Roblox to impact and contact with them. Objective: approximate to the Metaverse concept and its relationship with the advergaming, through the comparison between two population segments: 18-28-year-old university students from Spain and Mexico. Methodology: mixed qualitative-quantitative based on the content analysis-study of 4 brands in Roblox-and an exploratory survey (n=300). Results: the surveyed people do not generally know what the advergaming is and do not remember the advertisements they watched while playing videogames, but they mention spontaneously some brands used inside the videogame, mainly related to the fashion, technology and food industries and did not realize them being advertised. Conclusions: the results show that there are no significant differences between neither between sex, nor country of origin of the surveyed people. The videogames are the most extended and adopted way of metaverse currently. Facebook is the most known company as an example of metaverse related enterprise and the 30% of the survey believe that metaverse was created by Facebook. There is a lack of awareness about the terms related to the advertisement inside the videogames, nevertheless the players accept widely them while playing their favorite titles, even they qualify them as innovative.
【Abstract】The Metaverse is a new Internet application and social form that integrates a variety of new technologies. With the "carbon peak, carbon neutrality" goal and the proposal of a new power system, the construction of a power system in the metaverse is the trend of future development. For the application of the Metaverse in the power system, the Metaverse is recognized by means of digital twin technology, Internet of Things technology and other means, and then the energy storage power station system in the Metaverse is analyzed. To this end, this paper proposes a Metaverse-driven remote management scheme for energy storage power stations, and gives a specific design scheme. With the help of large-scale computing experiments and the parallel execution of virtual and real closed loops, the remote management and virtual-real interaction of the real energy storage power station system is realized, and the energy storage power station system is promoted from the management and control that relies on simulation to the intelligent management and control driven by the metaverse. In addition, in view of the demand of energy storage power station system for high-precision power load prediction, this paper also proposes a power load prediction model based on genetic algorithm-BP neural network. Considering the data characteristics, a scene-based classification model generation method is designed. The simulation results show that, compared with the BP neural network algorithm, the performance of the prediction model proposed in this paper has been significantly improved, and it can achieve effective prediction of power load.
【Abstract】Food delivery systems are gaining popularity recently due to the expansion of internet connectivity and for the increasing availability of devices. The growing popularity of such systems has raised concerns regarding (i) Information security, (ii) Business to business (B2B) deep discounting race, and (iii) Strict policy enforcement. Sensitive personal data and financial information of the users must be safeguarded. Additionally, in pursuit of gaining profit, the restaurants tend to offer deep discounts resulting in a higher volume of orders than usual. Therefore, the restaurants and the delivery persons fail to maintain the delivery time and often impair the food quality. In this paper, we have proposed a blockchain and smart contract-based food delivery system to address these issues. The main goal is to remove commission schemes and decrease service delays caused by a high volume of orders. The protocols have been deployed and tested on the Ethereum test network. The simulation manifests a successful implementation of our desired system; with the payment being controlled by our system. The actors (restaurant, delivery-person or consumer) are bound to be compliant with the policies or penalized otherwise.
【Abstract】This paper examines the rationale behind the exploration by the vast majority of central banks of introducing central bank digital currencies. This phenomenon is discussed in the context of the main drivers of central bank interest, the crucial role of public money in supporting and complementing private money channels, the role of digital ledger technology in facilitating the delivery of both wholesale and retail central bank digital currencies, and innovation in the forms of money that this enterprise represents. The implications for domestic and international monetary system architectures in the immediate, short-term, and long-term will be discussed. It will be argued that the delivery of central bank digital currencies represents an important development in the future of money, and requires agreement of the public following a wide-ranging debate at all levels in society.
