• International journal of advanced smart convergence
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• v.8 no.1
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• pp.196-203
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• 2019

We have reviewed the potential impact of blockchain technology on the music industry by analyzing the views of academia and the industry experts. The music industry had rapid changes from the physical market to the digital market in the past decades. The consumers download and stream music online and mobile during the digital dominant market. While streaming music has been recently growing at a fast rate, fair distribution of revenue to the artists continues to be an issue. Some industry experts believe that the issue of fair distribution of revenue to the artist may be resolved using blockchain technology, while some are skeptical about the application or the duration of impact. The blockchain may enhance speedier payment using smart contracts, provide additional revenue and promote the music if excellent fan support is achieved. The positive impact on the music industry may only be possible if there are detailed consideration of the industry and careful understanding of the customers.

• Journal of IKEEE
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• v.23 no.4
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• pp.1343-1352
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• 2019

To manage the Internet of Things(IoT) Network, which consists of a large number of various devices, a secure and automatic method of strengthening the IoT network is being proposed. Blockchain has a 'smart contract' element of autonomous execution method, which is emerging as a way to not only exchange data quickly without mediators but also securely and automatically manage processes between IoT devices. In this paper, we implement a prototype of the entire IoT device management system based on the EOSIO with DPoS(Distributed Proof of Stake)-based blockchain structure, proposed as a prior study, including the user application DApp(Decentralized Application) and the actual IoT devices (Raspberry Pi-based device, and smart lamp) that interact with the blockchain platform. We analyze the benefits of the system and measure the time overhead to show the feasibility of the system.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.12
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• pp.321-332
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• 2020

Decentralized approaches are extensively researched by academia and industry in order to cover up the flaws of existing systems in terms of data privacy. Blockchain and decentralized learning are prominent representatives of a deconcentrated approach. Blockchain is secure by design since the data record is irrevocable, tamper-resistant, consensus-based decision making, and inexpensive of overall transactions. On the other hand, decentralized learning empowers a number of devices collectively in improving a deep learning model without exposing the dataset publicly. To motivate participants to use their resources in building models, a decent and proportional incentive system is a necessity. A centralized incentive mechanism is likely inconvenient to be adopted in decentralized learning since it relies on the middleman that still suffers from bottleneck issues. Therefore, we design an incentive model for decentralized learning applications by leveraging the Ethereum smart contract. The simulation results satisfy the design goals. We also outline the concerns in implementing the presented scheme for sensitive data regarding privacy and data leakage.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.306-308
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• 2019

기존의 학력인증 서비스는 학교에 직접 방문하거나, 온라인을 통해 종이 증명서를 발급받는다. 하지만 학력인증을 블록체인에 기록하여, 인증 서비스의 비용을 줄이고 절차를 간소화하고자 한다. 더불어, 디지털 증명서를 블록체인에 등록하여 발급해온 증명서의 진위 여부를 확인하는 체제가 잘 갖춰지지 않은 곳에서도 재확인이 필요 없는 서비스를 제공하고자 한다. 블록체인에 증명서를 등록하는 중요한 기능은 '스마트 컨트랙트'를 통해 이루어진다. 매년 졸업요건이 변경된다는 점을 고려하면 스마트 컨트랙트에서 블록체인에 학력인증이 등록되는 조건의 업데이트는 필수불가결이다. 하지만 새로운 스마트 컨트랙트를 배포하는 식의 컨트랙트 업데이트는 여러 문제점들이 있다. 이를 해결하고자 본 논문에서는 proxy contract를 이용한 학력인증 서비스 시스템의 설계를 다루고자 한다.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1017-1029
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• 2023

A large amount of transactions are taking place through Blockchain. Among them, the proportion of transactions through smart contracts is increasing. Accordingly, problems such as vulnerability attacks on smart contracts and fraud using smart contracts are increasing. Through security audits of smart contracts, developers can discover and resolve vulnerabilities, and users can distinguish whether smart contracts are fraudulent. However, there are currently no regulations and standards for security auditing of smart contracts, so services that perform security auditing are uneven. In this paper, we analyze security audit trends for smart contracts and identify what services are being provided. We investigate what elements are analyzed from smart contracts, focusing on security audit reports. Also, investigate what vulnerabilities can be detected. Finally, we investigate quality indicators for smart contracts and visualization elements of design extraction. Through this, we hope to be able to find visualization elements specialized for smart contracts.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1789-1797
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• 2017

It is necessary to charge electric vehicles in order to drive them. Thus, it is essential to have electric vehicle charging facilities in place. In the case of a household battery charger, the power similar to that consumed by a household with a basic contract power of 3kW is consumed. In addition, many consumers who own an electric vehicle will charge their vehicles at the same time. The simultaneous charging of electric vehicles will cause the load to increase, which then will lead to the imbalance of supply and demand in the distribution system. Thus, a smart charging scheme for electric vehicles is an essential element. In this paper, simulated conditions were set up using real data relating to Korea in order to design a smart charging technique suitable for the actual situation. The simulated conditions were used to present a smart charging technique for electric vehicles that disperses electric vehicles being charged simultaneously. The EVs and Smart Charging Technique are modeled using the Electro Magnetic Transients Program (EMTP).

• Journal of the Korea Society for Simulation
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• v.22 no.2
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• pp.85-91
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• 2013

Smart phones become essential goods for our life. As the technology are developing, and the market becomes saturated, it is important to understand the determinants affecting purchase of smart phones. In this paper, to understand these determinants factor analysis and binary logistics regression is used. Toward this, we first define the determinants into 3 categories: customer satisfaction, switching barrier, and switching attractiveness based on literature review. Furthermore, we develop 9 hypotheses to test with survey data using factor analysis and binary logistics regression. The results show that the six factors (data quality, price satisfaction, corporate image, the burden of new contract, attraction of devices and attraction of other competitors) are significant when customers buy smart phones.

• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.174-184
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• 2019

In this study, we present a new scheme for smart education utilizing the concept of a blockchain for question sharing. A two-phase encryption technique for encrypting question papers (QSPs) is proposed. In the first phase, QSPs are encrypted using a timestamp, and in the second phase, previously encrypted QSPs are encrypted again using a timestamp, salt hash, and hash from the previous QSPs. These encrypted QSPs are stored in a blockchain along with a smart contract that helps the user to unlock the selected QSP. An algorithm is also proposed for selecting a QSP for the exam that randomly picks a QSP. Moreover, a timestamp-based lock is imposed on the scheme so that no one can decrypt the QSP before the allowed time. Security analysis is conducted to demonstrate the feasibility of the proposed scheme against different attacks. Finally, the effectiveness of the proposed scheme is demonstrated through implementation, and the superiority of the proposed scheme over existing schemes is proven through a comparative study based on different features.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.153-161
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• 2022

Among all industries, the construction industry still remains a traditional one with low productivity due to its labor-intensive and field-dependent production system, its supplier-oriented industrial structure, and the disruption of the information flow between participants. In addition, the construction industry in South Korea has recently been required to transform itself according to social trends such as aging, the reduction of skilled workers, and the shortening of working hours, and the disaster and death rates in the industry, which are more than twice as high as those in other industries, are making it more necessary to solve chronic safety problems. Therefore, the purpose of this study is to grasp the actual condition of safety management on construction sites in South Korea and analyze cases of K-smart technology utilization for preventing safety accidents on construction sites. The study investigated and analyzed the following. First, construction sites in South Korea were analyzed by type of safety accident, by type of construction, and by construction contract amount. Second, the current status of accidents on small-sized construction sites with a high fatal accident rate and cases of safety accidents on construction sites were investigated. The results of the study are expected to contribute to the dissemination and spread of smart safety technology for not only identifying major factors in safety accidents that occur on construction sites but also preventing workers from suffering accidents.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.6
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• pp.1103-1112
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• 2022

Blockchain technology is widespread in everyday life and various industry fields. It guarantees integrity and transparency between blockchain network participants through a distributed ledger. The smart contract is modifying and managing the distributed ledger, which is the most important component of guaranteeing integrity and transparency of blockchain network. Still, smart contracts are also a component of blockchain networks, it is disclosed to network participants transparently. For this reason, the vulnerability of smart contracts could be revealed easily. To mitigate this, various studies are leveraging TEE to guarantee the confidentiality of smart contracts. In existing studies, TEE provides confidentiality of smart contracts but guaranteeing the integrity of smart contracts is out of their scope. In this study, we provide not only the confidentiality of smart contracts but also their integrity, by guaranteeing the CFI of smart contracts within TEE.