• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.164-167
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• 2012

합의는 분산 시스템 환경에서 해결해야 할 근본적인 문제 중 하나이다. 특히 노드 또는 프로세스의 임의적인 실패 즉, 비잔틴 실패가 발생하였을 때 합의 문제는 더 복잡해진다. 본 연구에서는 동적인 노드의 가입과 탈퇴가 자유로운 클라우드 환경에서 비잔틴 합의 문제를 해결하기 위한 가쉽 알고리즘을 제안한다. 제안하는 알고리즘에서 확장성과 결함 포용의 특성을 내재한 가쉽 알고리즘을 적용함으로써 클라우드 환경에서의 비잔틴 합의 문제를 확장적이고 결함 포용적으로 해결할 수 있다. 알고리즘의 성능을 분석하기 위해 성능 평가를 수행하였다.

• SUVANNABHUMI
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• v.14 no.1
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• pp.89-108
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• 2022

Using Peter Barry's conception of "outdoor environment" in discoursing nature and culture, this article analyzes images of the countryside in the short stories "Dưới bóng hoàng lan" ("In the Ylang-Ylang Shade") by Thạch Lam (Thach Lam) and "Антоновские яблоки" ("Antonov Apples") by Иван Бунин (Ivan Bunin). The two share portray the Eastern Lands, as may be seen in Vietnamese northern countryside and the East Slavic, Byzantine. The paper focuses on three aspects of the countryside-cultural values; traces of urban life and; the aspirations of people. The article aims to emphasize people's desire to return to a type of nature that bears traces and harmonizes with human cultures.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.37-44
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• 2023

In the future society, a means to verify the identity of the information owner is required at the beginning of most services that the information owner encounters, and the emergence and gradual spread of digital identification that proves the identity of the information owner is essential. In addition, as the utilization value of personal information increases, discussions on how to provide personal information are active. Therefore, there is a need for a personal information management method necessary for building a hyper-connected society that is safe from various hacking, forgery, alteration, and theft by allowing the owner to directly manage and provide personal information management. In this study, a decentralized identity information management model that overcomes the problems and limitations of the centralized identity management method of personal information and manages and selectively provides personal information by the information owner himself and implemented a smart personal information provision system(SPIPS: Smart Personal Information Provision System) using a smartphone.

• International Journal of Computer Science & Network Security
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• v.23 no.6
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• pp.181-192
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• 2023

Blockchain system brought innovation in the area of accounting, credit monitoring and trade secrets. Consensus algorithm that considered the central component of blockchain, significantly influences performance and security of blockchain system. In this paper we presented four consensus protocols specifically as Proof of Work (PoW), Proof of Stake (PoS), Delegated Proof of Stake (DPoS) and Practical Byzantine Fault-Tolerance (PBFT), we also reviewed different security threats that affect the performance of Consensus Protocols and precisely enlist their counter measures. Further we evaluated the performance of these Consensus Protocols in tabular form based on different parameters. At the end we discussed a comprehensive comparison of Consensus protocols in terms of Throughput, Latency and Scalability. We presume that our results can be beneficial to blockchain system and token economists, practitioners and researchers.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.193-194
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• 2020

블록체인의 활용이 다양해지며 블록체인을 통한 산업, 정부의 기술적용이 확산되고 있다. 특히 사물인터넷 등 빅데이터 관리를 위한 방법으로 블록체인과의 융합도 적지 않게 거론되고 있다. 사물인터넷과 같은 빅데이터를 효과적으로 관리하기 위해서는 수집 및 저장과정과 더불어 투명하고 정확한 신뢰기반의 데이터 관리가 필요하다. 현재 블록체인의 프라이빗 블록체인 플랫폼에서 가장 많이 제시되고 활용되는 합의알고리즘은 PBFT이다. PBFT의 경우 노드 증가에 따른 연산알고리즘의 과중으로 인한 속도저하가 문제가 될 수 있다. 본 논문에서는 PBFT의 합의과정에 대한 알고리즘을 수정하여 노드 증가 시에도 복잡도를 낮출 수 있는 방법을 제안하였다. 본 논문에서는 시뮬레이션을 통하여 노드 개수를 변형하며 기존 PBFT알고리즘 대비 제안 알고리즘의 우수성을 증명한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.334-336
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• 2021

허가형 블록체인 기반 데이터 공유 시스템은 분산 환경에서 신뢰 수준을 구축하고 일관된 메시지를 기록 및 공유함으로써 서비스의 상호 운용성을 가능하게 한다. 그러나 허가형 블록체인은 종종 탈중앙화, 보안 및 상호 운용성과 충돌한다. 이는 중앙 집중식 시스템으로 돌아가거나 데이터의 독점 및 남용 및 오용으로 이어질 수 있다. 따라서 CAP (Consistency, Availability, Partition tolerance)에 이론 검증에 따라 메시지 공유, 비잔틴 내결함성 및 메시지 일관성을 고려하고 적용해야 한다. 기존의 PBFT(Practical Byzantine Fault Tolerance) 합의 알고리즘는 노드의 증가시, 장애내성을 갖기위해 계산되어야 할 합의 처리시간이 증가하며, DPOS(Delegated Proof of Stake) 알고리즘은 보상, 리더 선출의 공정성 문제 등에 따라 허가형 블록체인에서의 적합한 방식이 연구되고 있다. 본 논문에서는 서비스의 상호 운용성과 과제에 대해 논의하고 허가된 블록체인의 합의 개선을 통한 데이터 공유 시스템을 제안한다.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.741-754
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• 2022

Openstack is widely used as a representative open-source infrastructure of the service (IaaS) platform. The Openstack Identity Service is a centralized approach component based on the token including the Memcached for cache, which is the in-memory key-value store. Token validation requests are concentrated on the centralized server as the number of differently encrypted tokens increases. This paper proposes the practical Byzantine fault tolerance (PBFT) blockchain-based Openstack Identity Service, which can improve the performance efficiency and reduce security vulnerabilities through a PBFT blockchain framework-based decentralized approach. The experiment conducted by using the Apache JMeter demonstrated that latency was improved by more than 33.99% and 72.57% in the PBFT blockchain-based Openstack Identity Service, compared to the Openstack Identity Service, for 500 and 1,000 differently encrypted tokens, respectively.

• Journal of Korean Library and Information Science Society
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• v.53 no.4
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• pp.1-23
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• 2022

The record is both an palmistry and a fingerprint for human life and world of knowledge. Books, which are synonymous with records, are a channel through which history is traced and a window to savor. And the most primitive form of the book is the classics of ancient Greece and Rome, and the best part is the manuscript. It refers to the original recorded on papyrus, parchment, paper, etc. and the translated and translated copies of them. If we reflect on the long history of knowledge and culture, the classic manuscripts have continued to scatter and collect like a river flowing through time and space due to not only natural disasters, but also artificial cultural vandalism and the bibliocaust. Therefore, this study traced and linked the wandering and library return of classic manuscripts from ancient Greece to the medieval Renaissance period. As a result, dynasties and empires, monarchs and prime ministers, generals and conquerors, nobles and wealthy, clergy and scholars concentrated on collecting and translating classical manuscripts. If the ancient Greek and Roman scholars did not record knowledge and wisdom in papyrus and parchment, the medieval Byzantine and Islamic Empires did not collect, translate and reproduce classics, the book hunters didn't keep track of the classics, the Renaissance humanists did not restore and reinterpret the classics through intellectual exodus, and the historical library did not collect and preserve the classics and their translations, modern people would not have access to classical knowledge. Nevertheless, the tracing of classical manuscripts is an aporia in which many difficulties and contradictions overlap in the tracing of classic manuscripts due to historical flow, geographical wandering, and linguistic transformation. When a new manuscript is discovered and interpreted, correction and supplementation are inevitable, so the pursuit of the wandering and return of the classic manuscripts through follow-up research must be continued.

• KIEAE Journal
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• v.17 no.2
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• pp.21-28
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• 2017

Purpose: The early churches such as tabernacle, temple and synagogue had played a important role to form space concepts of western churches. Tabernacle and temple were designed with vertical axis which consisted of sanctuary, sanctum, outdoor yard. Synagogue was designed pew of congregation around pulpit to give a sermon. The aim of this paper is to analyze spatial principles of churches designed with vertical axis and centralized plan. Method: The concept of vertical axis plan succeeded to Basilica, Romanesque and Gothic churches, and the concept of centralized plan succeeded to Byzantine and Renaissance churches. Therefore, this paper analyzed spatial characteristics and role of light in churches according to epoch, and was progressed by examining the existing researches and case studies. Result: The churches designed with vertical axis plan realized spatial composition to show the concept of domus dei, and worship space was illuminated with mysterious light. The churches designed with centralized plan realized spatial composition to show the concept of domus ecclesiae, and light created dramatic holiness in worship space.

• Journal of the Korea Fashion and Costume Design Association
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• v.7 no.1
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• pp.15-31
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• 2005

Suhainmyuldo(수하인물도) is a kind of picture which express a person under the tree and is known to be transmitted from the Middle Asia. The origin of this kind of expression is assumed to be from Iykshini(=Iygsha), the fairy of tree, in India of from the 'Tree of Life' in W. Asia, and they had in fluenced on the craft art design of Chinese art. However, Chinese art had already developed the motif of this kind in its unique way. For example, Jookrimchilhundo(죽림칠현도: seven wise men in bamboo forest), during Six Dynasty. The tree of life(arbor vitae, lignum viate), the origin of the Painting of figure under a tree(수하인물도), was spreaded in several regions around the center of Mesopotamia early, and them transmitted to Sasan dynasty of Persia, even to Islam, Byzantine, Romanesque, ancient East Asia. The mural painting found in the 4th Tongu Ogoe tomb, which was created after the 5th Tongu Ogoe tomb, used Obangsaek more than the 5th tomb painting did. (The term Obansaek refers to the five Korean traditional colors consisted of yellow, blue, white, red and black) The mural painting on the 4th Ogoe tomb employed distinct technique to depict an object in a certain color by painting the surroundings with different primary colors, making the painting look more exotic and mysterious.