• International Journal of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.231-238
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• 2023

As the demand for distance education increases, interest in the management of learners' rights is increasing. Blockchain technology is a technology that guarantees the integrity of the learner's learning history, and enables learner-led learning control, data security, and sharing of learning resources. In this paper, we proposed a blockchain technology-based learning management system based on Hyperledger Fabric that can be verified through permission between nodes among blockchain platforms. Learning resources can be shared differentially according to the learning progress. Also the percentage of individual learners that can be managed. As a result of the study, the superiority of the platform in terms of convenience compared to the existing platform was demonstrated. As a result of the performance evaluation for the research in this paper, it was confirmed that the convenience was improved by more than 5%, and the performance was 4-5% superior to the existing platform in terms of learner satisfaction.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.572-575
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• 2022

최근 데이터의 불변성에 의하여 NFT와 같은 블록체인 기술이 각광받고 있으며, 그에 따라 스마트 계약의 사용량 또한 증가하는 추세이다. 하지만 스마트 계약에 다양한 보안 취약점이 존재하며 배포 후에는 수정을 할 수 없는 스마트 계약 특성상 사전에 해당 취약점을 탐지하는 기술의 중요성이 대두되고 있다. 따라서 본 논문에서는 인공신경망 기반의 스마트 계약의 취약점을 탐지하는 기법 연구 동향에 대하여 알아본다.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.9-12
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• 2020

에어비엔비와 같은 공유숙박시스템은 하루 400 만명 이상 이용하고 있는 거대한 시장이다. 일반적으로 지출해야 할 숙박비용보다 더 저렴한 가격이나 좋은 조건으로 머물 곳을 찾을 수 있다는 점에서 많은 사람들이 이용하고 있다. 그러나 호스트와 게스트에게 부담되는 과도한 수수료 문제가 존재한다. 또한 기존의 공유숙박 시스템은 호스트가 게스트에게 직접 비밀번호나 열쇠를 전달하기 때문에 보안 상의 이슈가 발생한다. 본 연구는 공유숙박시스템에 스마트 컨트랙트 기술을 도입하여 해당 이슈들을 개선, 해결하여 더 안전하고 합리적인 공유숙박시스템을 제안한다.

• 중국학논총
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• no.63
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• pp.205-224
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• 2019

The results of the studies of China and Vietnam are as follows. First of all, in China, the labor market in China has been fully completing laws and regulations since the implementation of the labor contract law in 2008. Specifically, we analyzed the labor market in China for labor contracts, recruitment, and minimum wage. Next, in Vietnam, which the tertiary and quaternary industries are rapidly developing. The labor market is expected to increase because demand for foreign manpower, as the advancement of retail, finance, tourism services, Smart factories in the textile and sewing- do. The limitations of this study, however, are that there is not enough data to utilize official data for labor market analysis in China and Vietnam. If a practical investigation is conducted for analyzing the labor market in Vietnam due to the changes in the labor market

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.265-267
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• 2023

스마트 컨트랙트는 작성된 코드에 의해 정의되어 실행조건이 충족될 시 자동으로 실행되는 전자 계약으로 다양한 분야에서 활용될 수 있다. 스마트 컨트랙트가 블록체인 네트워크에 배포되면 수정이 불가한데, 개발자들이 스마트 컨트랙트를 작성하는데 코드 패턴 재상용 하는 경우가 대다수이다. 이로 인한 스마트 컨트랙트 취약점 사고를 예방하기 위해 개발 단계에서 보안을 고려하여 스마트 컨트랙트 작성이 필요하다. 본 논문에서는 대표적인 스마트 컨트랙트에 대한 보안 취약점을 확인하고 보안 권장 사항을 정리한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.447-450
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• 2023

Blockchain technology has paved the way for the rise of non-fungible tokens(NFTs) in recent years. NFTs enable the unique ownership of digital assets and harness the power of blockchain's transparency and decentralization. However, existing NFT platforms often pose barriers to entry for the public due to their technical complexity and high issuance costs. To address the problem, this paper proposes a user-friendly NFT platform with a simplified issuance process. A home page is created to allow easy NFT issuance for anyone. These advancements are expected to foster the growth of the NFT market and facilitate the development of new business models.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.1247-1249
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• 2023

스마트 컨트랙트는 블록체인 상에서 실행되는 프로그램으로 복잡한 비즈니스 논리를 처리할 수 있다. 그러나 블록체인의 무결성과 조건에 따라 실행되는 특성을 이용한 악의적 사용으로 인하여 블록체인 보안에서 시급한 문제가 되고있다. 따라서 스마트 컨트랙트 취약성 탐지문제는 최근 많은 연구가 이루어지고 있다. 그러나 기존 연구의 대부분이 단일 유형의 취약성 여부에 대한 탐지에만 초점이 맞춰져 있어 여러 유형의 취약성에 대한 동시 식별이 어렵다. 이 문제를 해결하고자 본 연구에서는 스마트 컨트랙트 소스코드 제어 흐름 그래프를 기반으로 그래프의 forward edge와 backward edge를 고려한 신경망으로 그래프 구조를 학습한 후 그래프 multi-label classification을 진행하여 다중 취약성을 탐지할 수 있는 모델을 제안한다.

• Journal of information and communication convergence engineering
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• v.22 no.1
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• pp.64-69
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• 2024

Blockchain is a decentralized network in which data blocks are linked. Through a decentralized peer-to-peer network, users can create shared databases, resulting in a trustworthy and aggregated database known as a blockchain that enhances reliability and security. The distributed nature of the blockchain enables data to be stored on multiple nodes, eliminating the need for a central server or platform. This disintermediation significantly reduces the transaction and administrative costs. The blockchain is particularly valuable in applications where reliability and stability are critical because it establishes an open database that ensures data integrity, making it virtually impossible to tamper with or falsify data. This study explores the diverse applications of the blockchain technology in virtual assets, such as cryptocurrency, decentralized finance, central bank digital currency, nonfungible tokens, and metaverses. In addition, it analyzes the potential prospects and developments driven by these innovative technologies.

• The Journal of Industrial Distribution & Business
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• v.9 no.6
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• pp.77-85
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• 2018

Purpose - The purpose of this study is to subdivide trade transaction-centered structure in a logistics/distribution industry system to apply blockchain, to establish and resolve with which types of technology, and to provide policy direction of government institution and technology to apply blockchain in this kind of industry. Research design, data, and methodology - This study was conducted with previous researches centered on cases applied in various industry sectors on the basis of blockchain technology. Results - General fields of blockchain application include digital contents distribution, IoT platform, e-Commerce, real-estate transaction, decentralized app. development(storage), certification service, smart contract, P2P network infrastructure, publication/storage of public documents, smart voting, money exchange, payment/settlement, banking security platform, actual asset storage, stock transaction and crowd funding. Blockchain is being applied in various fields home and abroad and its application cases can be explained in the banking industry, public sector, e-Commerce, medical industry, distribution and supply chain management, copyright protection. As examined in the blockchain application cases, it is expected to establish blockchain that can secure safety through distributed ledger in trade transaction because blockchain is established and applied in various sectors of industries home and abroad. Parties concerned of trade transaction can secure visibility even in interrupted specific section when they provide it as a base for distributed ledger application in trade and establish trade transaction model by applying blockchain. In case of interrupted specific section by using distributed ledger, blockchain model of trade transaction needs to be formed to make it possible for parties concerned involved in trade transaction to secure visibility and real-time tracking. Additionally, management should be possible from the time of contract until payment, freight transfer to buyers through land, air and maritime transportation. Conclusions - In order to boost blockchain-based logistics/distribution industry, the government, institutionally, needs to back up adding legal plan of shipping, logistics and distribution, reviewing standardization of electronic switching system and coming up with blockchain-based industrial road maps. In addition, the government, technologically, has to support R&D for integration with other high technology, standardization of distribution industry's blockchain technology and manpower training to expand technology development.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.11
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• pp.403-410
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• 2022

Non-Fungible Tokens (NFTs) created on the basis of blockchain have their own unique value, so they cannot be forged or exchanged with other tokens or coins. Using these characteristics, NFTs can be issued to digital assets such as images, videos, artworks, game characters, and items to claim ownership of digital assets among many users and objects in cyberspace, as well as proving the original. However, interest in NFTs exploded from the beginning of 2020, causing a lot of load on the blockchain network, and as a result, users are experiencing problems such as delays in computational processing or very large fees in the mining process. Additionally, all actions of users are stored in the blockchain, and digital assets are stored in a blockchain-based distributed file storage system, which may unnecessarily expose the personal information of users who do not want to identify themselves on the Internet. In this paper, we propose an NFT platform using cloud computing, access gate, conversion table, and cloud ID to improve usability and privacy problems that occur in existing system. For performance comparison between local and cloud systems, we measured the gas used for smart contract deployment and NFT-issued transaction. As a result, even though the cloud system used the same experimental environment and parameters, it saved about 3.75% of gas for smart contract deployment and about 4.6% for NFT-generated transaction, confirming that the cloud system can handle computations more efficiently than the local system.