• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.640-641
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• 2019

비트코인으로 대표되는 블록체인은 2009년 이후 여러 산업군에서 블로체인이 만들어져 특정 사업에서 utility 기능을 수행하는 것을 목표로 개발되어 유통되고 있다. 하지만 블록체인은 실생활에 사용하기에는 많은 문제로 활성화가 안되고 있다. 본 연구는 블록체인의 운영 시 발생하는 문제점을 블록체인 승인시스템을 통해 해결하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.231-232
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• 2022

본 논문에서는 직업 교육 분야에 인공지능 융합 교육을 위한 파이썬 블록과 텍스트 동시 코딩 플랫폼을 설계하였다. 플랫폼에 코딩 언어로는 데이터 분석과 머신러닝의 다양한 라이브러리를 지원하고 있는 파이썬으로 하며, 직업 교육의 영역 전문가가 쉽게 직무 기능 파이썬 블록 모듈을 만들어 추가하고 커스터마이징을 할 수 있는 아키텍처를 갖고 있다. 제안한 플랫폼을 활용한 인공지능 융합 직업 분야로 바이오와 기계공학 분야의 블록 모듈을 추가하고 실습 예제를 만드는 과정을 보여 플랫폼의 유용성과 효율성을 보였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.719-720
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• 2023

본 연구에서는 온라인 저지 문항을 블록 프로그래밍 언어로 학습하기 위한 방안에 대해서 탐구하였다. 온라인 저지를 활용한 프로그래밍 교육은 알고리즘을 설계하는 추상화 과정과 이를 프로그래밍 언어로 작성하는 자동화 과정이 포함되며 이는 컴퓨팅 사고력 발달에 영향을 준다. 온라인 저지는 대부분 텍스트 프로그래밍 언어(이하, TPL)에서 지원되어 초보 학습자가 사용하기에 어려움이 있다. 블록 프로그래밍 언어(이하, BPL)를 기반으로 한 온라인 저지는 BPL로 작성한 것을 TPL로 변환하는 방법과 그래픽 기반 문제상황을 해결하는 방법이 있으며 TPL로 변환하는 것은 텍스트 기반 온라인 저지 문항을 사용할 수 있으나 사용하는 방법이 어렵다. 반면 그래픽 기반 문제 상황은 사용하는 방법이 쉽지만 문항이 제한적이고 순차적 사고가 강조된다. 이에 엔트리 '스터디'와 '나의 학급-과제'를 이용하면 자동 평가 기능은 없지만 학습자가 익숙한 환경에서 학습할 수 있고 교사는 문항을 직접 개발할 수 있으며 문제 제시, 예시 작품 제시, 블록 제한, 과제제출 등을 사용하여 BPL에서 온라인 저지 문항을 학습할 수 있다.

• Review of KIISC
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• v.34 no.1
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• pp.27-32
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• 2024

블록체인 기반 NFT(Non-Fungible Token)는 자산 디지털화 및 소유권을 위한 독특한 기회를 제공하면서 디지털 경제를 변화시키는 원동력으로 등장했다. 블록체인 생태계 내에서 NFT의 급속한 출현은 디지털 자산 관리 및 소유권에 있어 중요한 발전을 의미한다. 본 연구는 기술 혁신, 시장 역학 및 규제 프레임워크의 역할을 강조하면서 블록체인 기반 NFT 서비스의 운영 전략을 검토하였다. 본 연구는 기술과 시장 역학의 교차점을 강조하면서 이더리움 블록체인에서 NFT의 기술적 토대, 확장성과 상호 운용성의 과제, 다양한 시장 관행의 의미를 연구한다. 디지털 경제에서 기능을 향상하는 것에 중점을 두고 NFT 표준화, 확장성 및 사용자 참여의 과제와 기회를 조사하여 다양한 시장 애플리케이션에 맞게 NFT 플랫폼을 최적화하는 데 대한 통찰력을 제공하는 것을 목표로 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1676-1686
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• 2021

In this paper, we propose a general cross-chain solution based on the idea of modularity, abstraction, and layering, which decoupling the cross-chain function from the consensus algorithm and specific application logic, and utilize a Merkle proof to ensure the validity and legality of cross-chain operations. Since the underlying implementations of homogeneous and heterogeneous blockchains are different, we treat them separately. For homogeneous blockchains, we suggest a TCP-like cross-chain transport protocol (CCTP). While for heterogeneous blockchains, we present a method to construct the relay chain to realize the cross-chain function. The proposed scheme can enable the correct, effective, reliable, orderly, and timely transmission of cross-chain data. However, the essential difference between the operations within a single blockchain and the interoperability between different blockchains is that the trust domain is different. Cross-chain interoperation itself breaks the completeness of the blockchain, therefore, some efficiency and safety must sacrifice to trade-off.

• Journal of the Korea Society for Simulation
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• v.32 no.4
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• pp.59-67
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• 2023

Private blockchains can apply enhanced security policies that allow only authorized users to participate in the blockchain network. In addition, when used in a career management system where the validity of an individual's career is important, it has the suitable characteristics in terms of information integrity. However, due to the excessive performance requirements of blockchain technology, identifying performance characteristics through simulation can be helpful in stable operation of the system. This paper presents research results that utilized performance evaluation results while constructing a career management system based on the Ethereum blockchain. The service not only serves as a portfolio that records personal career development activities, certification acquisition, and award results, but also provides a community function for career planning to strengthen employment competitiveness. In addition, we present how a compensation policy can be executed to encourage users to participate in career development through community activities. In particular, an appropriate compensation policy was derived by reviewing changes in performance characteristics in accordance with the transaction volume on Geth nodes.

• Journal of the Korea Institute of Building Construction
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• v.24 no.2
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• pp.227-238
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• 2024

This study addresses the escalating flood damages prompted by recent climate shifts characterized by extreme weather events and proposes rainwater infiltration blocks as a potential solution. Recognizing the limitations inherent in existing inundation simulation methods, we advocate for the integration of novel functionalities, particularly leveraging drone technology. Our research endeavors encompass experimental assessments of inundation and flooding simulation technologies. These evaluations are conducted within areas where rainwater infiltration storage blocks have been implemented, juxtaposed against existing programs utilizing Digital Elevation Models(DEM) and Digital Surface Models(DSM). Through this comparative analysis and a meticulous scrutiny of the adaptability of inundation and flooding simulation to real-world deployment scenarios, we ascertain the efficacy of the simulation program as a decision-making tool for identifying optimal sites for rainwater infiltration storage block installation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.4
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• pp.21-30
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• 2009

Fusion flash memory such as OneNAND$^{TM}$ is popular as a ubiquitous storage device for embedded systems because it has advantages of NAND and NOR flash memory that it can support large capacity, fast read/write performance and XIP(eXecute-In-Place). Besides, OneNAND$^{TM}$ provides not only advantages of hybrid structure but also multi-block erase function that improves slow erase performance by erasing the multiple blocks simultaneously. But traditional NAND Flash Translation Layer may not fully support it because the garbage collection of traditional FTL only considers a few block as victim block and erases them. In this paper, we propose an Erase Group Flash Translation Layer for improving multi-block erase function. EGFTL uses a superblock scheme for enhancing garbage collection performance and invalid block management to erase multiple blocks simultaneously. Also, it uses clustered hash table to improve the address translation performance of the superblock scheme. The experimental results show that the garbage collection performance of EGFTL is 30% higher than those of traditional FTLs, and the address translation performance of EGFTL is 5% higher than that of Superblock scheme.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.315-320
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• 2021

While blockchain platforms for various purposes have been developed and the blockchain ecosystem is being developed, interoperability problems are emerging in which each blockchain is isolated and operated. In this study, we introduce interchain and sidechain technologies, which are blockchain that connect blockchain, and explain examples of using heterogeneous blockchain transactions and functions by applying them. In addition, blockchain, artificial intelligence, and IoT technologies, which are drawing attention in the fourth industrial revolution, are going through a process of converging and developing beyond their own development. In this regard, we present processes for combining artificial intelligence or IoT in blockchain, and propose a model that can operate without intervention by applying the combination of blockchain and artificial intelligence IoT to processes for trading and exchange between heterogeneous blockchain.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.3
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• pp.201-207
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• 2021

Deep learning, a type of machine learning, performs learning while changing the weights as it progresses through each learning process. Tensor Flow and Keras provide the results of the end of the learning in graph form. Thus, If an error occurs, the result must be discarded. Consequently, existing technologies provide a function to roll back learning results, but the rollback function is limited to results up to five times. Moreover, they applied the concept of MLOps to track the deep learning process, but no rollback capability is provided. In this paper, we construct a system that manages the intermediate value of the learning process by blockchain to record the intermediate learning process and can rollback in the event of an error. To perform the functions of blockchain, the deep learning process and the rollback of learning results are designed to work by writing Smart Contracts. Performance evaluation shows that, when evaluating the rollback function of the existing deep learning method, the proposed method has a 100% recovery rate, compared to the existing technique, which reduces the recovery rate after 6 times, down to 10% when 50 times. In addition, when using Smart Contract in Ethereum blockchain, it is confirmed that 1.57 million won is continuously consumed per block creation.