• Title, Summary, Keyword: BlockChain

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A Study on Implementation of BlockChain Voting System using Hyperledger Fabric (Hyperledger Fabric을 활용한 블록체인 투표시스템 구현에 관한 연구)

  • Hwang, Won-Yong;Kim, Hyo-Kwan
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.4
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    • pp.298-305
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    • 2020
  • This paper deals with the implementation of electronic voting system using permissioned block chain technology. Cases studies have recently been under way in many industrial areas to review the application of the blockchain based electronic voting system. The existing electronic voting system was easily exposed by hacking because of its centralized characteristics, making it difficult to ensure the reliability and transparency of the voting system itself. In this study, we proposed key considerations and concepts to ensure the reliability and transparency of voters and voting stakeholder by utilizing a hyperledger fabric which is nowadays widely used as a permissioned blockchain.

The Probabilistic Analysis of Fatigue Damage Accumulation Behavior Using Markov Chain Model in CFRP Composites (Markov Chain Model을 이용한 CFRP 복합재료의 피로손상누적거동에 대한 확률적 해석)

  • Kim, Do-Sik;Kim, In-Bai;Kim, Jung-Kyu
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.4
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    • pp.1241-1250
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    • 1996
  • The characteristics of fatigue cumulative damage and fatigue life of 8-harness satin woven CFRP composites with a circular hole under constant amplitude and 2-level block loading are estimated by Stochastic Makov chain model. It is found in this study that the fatigue damage accumulation behavior is very random and the fatigue damage is accumulated as two regions under constant amplitude fatigue loading. In constant amplitude fatigue loading the predicted mean number of cycles to a specified damage state by Markov chain model shows a good agreement with the test result. The predicted distribution of the fatigue cumulative damage by Markov chain model is similar to the test result. The fatigue life predictions under 2-level block loading by Markov chain model revised are good fitted to the test result more than by 2-parameter Weibull distribution function using percent failure rule.

Optimal Maintenance Policy Using Non-Informative Prior Distribution and Marcov Chain Monte Carlo Method (사전확률분포와 Marcov Chain Monte Carlo법을 이용한 최적보전정책 연구)

  • Ha, Jung Lang;Park, Minjae
    • Journal of Applied Reliability
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    • v.17 no.3
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    • pp.188-196
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    • 2017
  • Purpose: The purpose of this research is to determine optimal replacement age using non-informative prior information and Bayesian method. Methods: We propose a novel approach using Bayesian method to determine the optimal replacement age in block replacement policy by defining the prior probability with data on failure time and repair time. The Marcov Chain Monte Carlo simulation is used to investigate the asymptotic distribution of posterior parameters. Results: An optimal replacement age of block replacement policy is determined which minimizes cost and nonoperating time when no information on prior distribution of parameters is given. Conclusion: We find the posterior distribution of parameters when lack of information on prior distribution, so that the optimal replacement age which minimizes the total cost and maximizes the total values is determined.

A Study on KSI-based Authentication Management and Communication for Secure Smart Home Environments

  • Ra, Gyeong-Jin;Lee, Im-Yeong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.2
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    • pp.892-905
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    • 2018
  • In smart home environment, certificate based signature technology is being studied by communication with Internet of Things(IoT) device. However, block - chain technology has attracted much attention because of the problems such as single - point error and management overhead of the trust server. Among them, Keyless Signature Infrastructure(KSI) provides integrity by configuring user authentication and global timestamp of distributed server into block chain by using hash-based one-time key. In this paper, we provide confidentiality by applying group key and key management based on multi - solution chain. In addition, we propose a smart home environment that can reduce the storage space by using Extended Merkle Tree and secure and efficient KSI-based authentication and communication with enhanced security strength.

Past, Present and Future of Blockchain Technology (블록체인 세대별 기술 동향)

  • Park, J.S.;Park, J.Y.;Choi, S.M.;Oh, J.T.;Kim, K.Y.
    • Electronics and Telecommunications Trends
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    • v.33 no.6
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    • pp.139-153
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    • 2018
  • The explosive interest in block chain, which was triggered by Bitcoin in 2009, is leading to substantial investment and the development of block chain technology. There is no dispute among experts that block chain will be the next generation of innovation. However, despite the high expectations for block chains, the related technology still has certain limitations. In addition to improving issues such as a low transaction throughput, inefficient agreement algorithms, and an inflexible governance structure, it is necessary to solve various problems for commercialization and full-scale spreading owing to the trilemma problem among the scalability, security, and decentralization. Under this situation, identification of the technology characteristics according to the generation is helpful for the development of the core technology requirements and commercialization blueprint in establishing an R&D direction. Therefore, in this article, the development of blockchain technology is divided into generations and analyzed in terms of the operational structure, consensus algorithm, governance, scalability, and security.

A Implementation of Blockchain based Manufacturing Supply Chain Tracking System (블록체인 기반 제조 공급망 추적 시스템 구현)

  • Lee, Jae-Ho;Nam, Ho-Ki
    • Journal of the Korea Safety Management & Science
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    • v.19 no.4
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    • pp.183-188
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    • 2017
  • Block Chain is a technology that records and shares distributed ledgers without a central authority, providing a decentralized platform for transparent transactions in the business and enhancing transparency and traceability in all transactions to ensure trust in the transaction. Despite initial doubts about this technology, it is committed to adopting, adapting and improving the technology in a wide range of industries, including finance, government, security, logistics, food, medical, legal, and real estate. This study examines this technology, its applicability and potential benefits to the manufacturing supply chain. A tracking system of manufacturing supply chain to visualize transparency and traceability is implemented, and the conditions for adopting the technology in the manufacturing supply chain and the issues to be addressed are discussed.

A NOTE ON FINITE CONDITIONS OF ORTHOMODULAR LATTICES

  • Park, Eun-Soon
    • Communications of the Korean Mathematical Society
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    • v.14 no.1
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    • pp.31-37
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    • 1999
  • We prove the following: every chain-finite OML is path-connected; every finite block of an OML L is path-connected with at least one other block in L; every OML with unifromly finite sites is path-connected.

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Norfloxacin Release from Polymeric Micelle of Poly($\gamma$-benzyl L-glutamate)/Poly(ethylene oxide)/Poly($\gamma$-benzyl L-glutamate)/ Block Copolymer

  • 나재운;정영일;조종수
    • Bulletin of the Korean Chemical Society
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    • v.19 no.9
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    • pp.962-967
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    • 1998
  • Block copolymers consisting of poly(rbenzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) as the hydrophilic part were synthesized and characterized. Polymeric micelles of the block copolymers (abbreviated GEG) were prepared by a dialysis method. The GEG block copolymers were associated in water to form polymeric micelles, and the critical micelle concentration (CMC) values of the block copolymers decreased with increasing PBLG chain length in the block copolymers. Transmission electron microscopy (TEM) observations revealed polymeric micelles of spherical shapes. From dynamic light scattering (DLS) study, sizes of polymeric micelles of GEG-1, GEG-2, and GEG-3 copolymer were 106.5±59.2 nm, 79.4±46.0 nm, and 37.9±13.3 nm, respectively. The drug loading contents of GEG-1, GEG-2 and GEG-3 polymeric micelles were 12.6, 11.9, and 11.0 wt %, respectively. These results indicated that the drugloading contents were dependent on PBLG chain length in the copolymer; the longer the PBLG chain length, the more the drug-loading contents. Release of norfloxacin (NFX) from the nanoparticles was slower in higher loading contents of NFX than in lower loading contents due to the hydrophobic interaction between PBLG core and NFX.

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A Study on Privacy and Information Protection in Distributed Network Environment - Focused on Blockchain - (P2P 분산 네트워크 환경 내 프라이버시 및 정보보호 방안 - 블록체인 중심으로 -)

  • Park, Sumin;Hong, Seng-phil
    • Journal of Security Engineering
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    • v.14 no.2
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    • pp.167-180
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    • 2017
  • The smart contract of the block chain is a technology that guarantees the reliable contract without intermediary third party, and various studies are being carried out in various fields. When smart contracts are placed on the block chain, if the sensitive information of the contracting parties is registered, it may become an example of infringement of personal information. However, research on privacy and information protection among the research using the block chain smart contract seems to be insufficient. In this paper, we propose a design method to solve this issue by deriving the issue of reliable block chain smart contract and contribute to making it safe to use in P2P distributed network environment through case study.

SPCBC: A Secure Parallel Cipher Block Chaining Mode of Operation based on logistic Chaotic Map

  • El-Semary, Aly M.;Azim, Mohamed Mostafa A.;Diab, Hossam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.7
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    • pp.3608-3628
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    • 2017
  • Several block cipher modes of operation have been proposed in the literature to protect sensitive information. However, different security analysis models have been presented for attacking them. The analysis indicated that most of the current modes of operation are vulnerable to several attacks such as known plaintext and chosen plaintext/cipher-text attacks. Therefore, this paper proposes a secure block cipher mode of operation to thwart such attacks. In general, the proposed mode combines one-time chain keys with each plaintext before its encryption. The challenge of the proposed mode is the generation of the chain keys. The proposed mode employs the logistic map together with a nonce to dynamically generate a unique set of chain keys for every plaintext. Utilizing the logistic map assures the dynamic behavior while employing the nonce guarantees the uniqueness of the chain keys even if the same message is encrypted again. In this way, the proposed mode called SPCBC can resist the most powerful attacks including the known plaintext and chosen plaintext/cipher-text attacks. In addition, the SPCBC mode improves encryption time performance through supporting parallelized implementation. Finally, the security analysis and experimental results demonstrate that the proposed mode is robust compared to the current modes of operation.