• Journal of Platform Technology
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• v.9 no.1
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• pp.46-57
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• 2021

Recently, research has been actively conducted to utilize blockchain technology in various fields. In particular, blockchain-based smart contracts are applied to various automation systems that require reliability as they have the characteristics of recording data in a distributed ledger environment to verify the integrity and validity of data. However, blockchain does not provide data access control and information security because data is shared among network participants. In this paper, we propose a user dynamic access control mechanism utilizing smart contracts in blockchain environments. The proposed mechanism identifies the user's contextual information when accessing data, allocating the user's role and dynamically controlling the data access range. This can increase the security of the system and the efficiency of data management by granting data access dynamically at the time of user authentication, rather than providing the same services in roles assigned to each user group of the network system. The proposed mechanism is expected to provide flexible authentication capabilities through dynamic data access control by users to enhance the security of data stored within blockchain networks.

• Informatization Policy
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• v.28 no.2
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• pp.3-33
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• 2021

The purpose of this study is to analyze the research trends in the field of Blockchain that is one of the core technologies of the 4^th Industry, and present future research orientation. In this study, (1) Blockchain technologies in business perspective are summarized; (2) analysis criteria of Blockchain fields are established; and (3) results of analysis are presented and future research orientation is proposed. Major findings are as follows: (1) related research is being activate with the advent of the 3rd generation blockchain which aims for distributed applications. (2) major concerns of the technology (engineering) field is blockchain scalability and of the business (application) field is blockchain-based supply chain traceability. (3) Compared to overseas, domestic research results are very poor. (4) to catchup the gap, the spreading of awareness that blockchain is not a technology but a business means is required.

• KNOM Review
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• v.22 no.3
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• pp.20-24
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• 2019

Blockchain is a distributed ledger-based technology where all nodes participating in the blockchain network are connected to the P2P network. When a transaction is created in the blockchain network, the transaction is propagated and validated by the blockchain nodes. The verified transaction is sent to peers connected to each node through P2P network, and the peers keep the transaction in the memory pool. Due to the nature of P2P networks, the number and type of transactions delivered by a blockchain node is different for each node. As a result, all nodes do not have the same memory pool. Research is needed to solve problems such as attack detection. In this paper, we analyze transactions in the memory pool before solving problems such as transaction fee manipulation, double payment problem, and DDos attack detection. Therefore, this study collects transactions stored in each node memory pool of Bitcoin and Ethereum, a cryptocurrency system based on blockchain technology, and analyzes how much common transactions they have using jacquard similarity.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.1-11
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• 2020

As an important basic building block of the smart grid environment, smart meter provides real-time electricity consumption information to the utility. However, ensuring information security and privacy in the smart meter data aggregation process is a non-trivial task. Even though the secure data aggregation for the smart meter has been a lot of attention from both academic and industry researchers in recent years, most of these studies are not secure against internal attackers or cannot provide data integrity. Besides, their computation costs are not satisfactory because the bilinear pairing operation or the hash-to-point operation is performed at the smart meter system. Recently, blockchains or distributed ledgers are an emerging technology that has drawn considerable interest from energy supply firms, startups, technology developers, financial institutions, national governments and the academic community. In particular, blockchains are identified as having the potential to bring significant benefits and innovation for the electricity consumption network. This study suggests a distributed, privacy-preserving, and simple secure smart meter data aggregation system, backed up by Blockchain technology. Smart meter data are aggregated and verified by a hierarchical Merkle tree, in which the consensus protocol is supported by the practical Byzantine fault tolerance algorithm.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.303-309
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• 2021

This study examines the effects of CBDC(Central Bank Digital Currency) on the Korean economy in the digital currency era and discusses the response strategies for CBDC. With the review of the definition and the development status of digital currency, we explore the characteristics and current status of CBDC in Korea as well as the possibility for internationalization of CBDC. The result shows that CBDC can reduce credit risk, improve transaction transparency compared to cash, and increases monetary policy capacity. Meanwhile, the credit and intermediary function of financial institutions may be weakened, and side effects such as financial alienation may occur. Nevertheless, as the issuance of CBDC is an important opportunity to enhance the possibility of internationalization of Korean Won, preemptive measures are required to keep pace with the competition and cooperation with each country toward the digital key currency. We need to accelerate the digital financial environment through Korea's comparative advantage, and develop a strategy to achieve the internationalization of the financial industry and the Korean Won through CBDC issuance. From the early stage of CBDC designing, it is necessary to achieve international agreements through cooperation with other central banks and to develop policies suitable for the transition to digital currency.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.731-751
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• 2021

The Internet of Things is a huge group of devices communicating each other and the interconnection of objects in the network is a basic requirement. Choosing a reliable device is critical because malicious devices can compromise networks and services. However, it is difficult to create a trust management model due to the mobility and resource constraints of IoT devices. For the centralized approach, there are issues of single point of failure and resource expansion and for the distributed approach, it allows to expand network without additional equipment by interconnecting each other, but it has limitations in data exchange and storage with limited resources and is difficult to ensure consistency. Recently, trust management models using fog nodes and blockchain have been proposed. However, blockchain has problems of low throughput and delay. Therefore, in this paper, a trust management model for selecting reliable devices in a fog-based IoT environment is proposed by applying IOTA, a blockchain technology for the Internet of Things. In this model, Directed Acyclic Graph-based ledger structure manages trust data without falsification and improves the low throughput and scalability problems of blockchain.

• The Journal of Society for e-Business Studies
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• v.23 no.3
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• pp.13-32
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• 2018

Btcoin has made a big progress through anonymity, decentralized authority, sharing economy, multi-ledger book-keeping, block-technology and the convenient financial vehicle. Bitcoin has the characteristics of mining and supply by decentralized suppliers, limited supply quantity and the partial money-like function as well as gold. The paper studies the hedge and safe-haven of Bitcoin and gold on daily frequency data over the period of July 20, 2010-Dec. 27, 2017 employing Asymmetric Vector GARCH. It finds that gold has the hedge and safe-haven against inflation and capital markets while Bitcoin has the weak hedge and the weak safe-haven. It shows insignificant effects of inflations of US and Korea on the volatilities of Bitcoin and gold. It also suggests the necessity of clearing of vagueness behind the anonymity for fair and transparent trade through the law application in the absence or fault in law (Lucken im Recht). following the spirit of the living constitution (lebendige gutes Recht oder Vorschrift). The relevant institutions are hoped to be given some of obligations such as registration, minimum required capital. report, disclosure, explanation, compliance and governance with autonomous corresponding rights. The study also suggests the reestablishment of the relevant financial law and taxation law. The hedge would not be successfully accomplished without the vigilant cautions of investors.

• Knowledge Management Research
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• v.23 no.1
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• pp.149-164
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• 2022

This paper analyzes the independent financial advisory business that is not yet active in Korea and proposes a plan to activate the independent financial advisory business using fintech technology. A bill was enacted in 2017 for the domestic independent financial advisory business, but it has not been activated much until now for various reasons. Although existing studies have proposed solutions in various ways, there is no clear solution yet. This paper proposes a new method of revitalizing the independent financial advisory business through fintech technology using the trust system that has recently attracted attention. Digital securities fintech technology using blockchain distributed ledger technology presents new possibilities in the real estate and music copyright markets, and related fintech venture companies continue to emerge in Korea. By combining these digital securities fintech technologies and the business process of ETF, a method was derived so that independent financial advisors can have their own financial products. The proposed model is more decentralized than the existing financial product sales structure, and presents the possibility of a protocol economy through a structure close to a private blockchain while complying with the existing financial order. This paper is meaningful in that it presented new solutions to completely different markets from information convergence perspectives on two completely different markets, and we hope that more business solutions will emerge through knowledge management activities that converge various perspectives in the future.

• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.267-273
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• 2010

The present study examined factors for current conditions of dental office manager in Korean dental clinic. 108 randomly selected members of Korean dental office manager responded to a questionnaire. A survey was conducted for a month from 1, June 2008, and the chi-square test and ANOVA were used in the statistical analysis. The findings of the study were as follows: The number of members depending on the type of occupation dental hospital was the highest number of members, members of the dental hygienist at the dental hospital number significantly higher. The career of dental office manager followed by 1-5 year in dental hospital, 5-10 year in dental network, 1-5 year in dental clinic accounting for 48%, 52.9%, 69.4%. The difficulty during duty performance are high expectation of owner in dental hospital, learning of dental office manager duty in dental clinic. The duty of dental office manager followed by customer service, appointment scheduling, telephone etiquette, treatment plan. Henceforth, it needs to standardize the Korean name of dental office manager and duty. Also, it have to an official certification system.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.10
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• pp.387-396
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• 2018

Stock price prediction has been a difficult problem to solve. There have been many studies to predict stock price scientifically, but it is still impossible to predict the exact price. Recently, a variety of types of cryptocurrency has been developed, beginning with Bitcoin, which is technically implemented as the concept of distributed ledger. Various approaches have been attempted to predict the price of cryptocurrency. Especially, it is various from attempts to stock prediction techniques in traditional stock market, to attempts to apply deep learning and reinforcement learning. Since the market for cryptocurrency has many new features that are not present in the existing traditional stock market, there is a growing demand for new analytical techniques suitable for the cryptocurrency market. In this study, we first collect and process seven cryptocurrency price data through Bithumb's API. Then, we use the gradient boosting model, which is a data-driven learning based machine learning model, and let the model learn the price data change of cryptocurrency. We also find the most optimal model parameters in the verification step, and finally evaluate the prediction performance of the cryptocurrency price trends.