• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.759-764
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• 2021

Because sensitive and private information should be exchanged between electric vehicles and a V2G service provider, reliable communication channel is essential to operate Vehicle-to-Grid (V2G) system which considers battery of electric vehicles as a factor of smart grid. The block chain is a platform for cryptocurrency transaction and fully distributed database system running by only equivalent node in the network without help of any central management or 3^rd party. In this paper, the structure and operation method of the blockchain are investigated, and the application of the blockchain for the V2G system was also explained and analyzed.

• Trans-
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• v.16
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• pp.33-68
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• 2024

In a rapidly growing digital economic environment, NFT has emerged as a hot topic in the art field. However, in China, NFT art is developing slowly due to constraints related to China's political economy and socio-cultural situation. Due to strict management and control, the circulation of cryptocurrency is limited, and the level of public awareness and acceptance of NFT art and market maturity are still low. Despite these limitations, this paper predicts that Chinese art creators and market participants can build an online personal art IP model that suits the characteristics of the Chinese market and explores the current status and possibilities.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.12-21
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• 2017

From 1960, the government decided to build apartment houses on a large scale in order to resolve the rising housing problems. However, the maintenance issues that have arisen from the deterioration of housing has not received adequate attention. The policy focuses only on the supply of housing. By passing new laws, the durable period during which buildings allowed reconstruction was increased, and long term maintenance plans were treated as important issues. The government was then obligated to establish certain long term maintenance plans and costs by legislating a Housing Act and requiring it be adjusted every three years. However, when planning long-term repair costs, doing so without considering the time value of money would become a problem. In addition, if differences between the planned repair costs and actual costs occur, it becomes necessary to adjust the long-term repair costs but, as of yet, the criteria to adjust such things does not exist. For these reasons, if there is lack of money to execute large-scale repair work, a building is unlikely to respond to deterioration of housing; on the other hand, an unnecessary reserve or pool of money can lead to conflict among residents. Therefore, this paper will propose estimation and adjustment models considering the time value of money for long term maintenance costs of apartment houses.

• The Journal of Society for e-Business Studies
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• v.23 no.3
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• pp.13-32
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• 2018

Btcoin has made a big progress through anonymity, decentralized authority, sharing economy, multi-ledger book-keeping, block-technology and the convenient financial vehicle. Bitcoin has the characteristics of mining and supply by decentralized suppliers, limited supply quantity and the partial money-like function as well as gold. The paper studies the hedge and safe-haven of Bitcoin and gold on daily frequency data over the period of July 20, 2010-Dec. 27, 2017 employing Asymmetric Vector GARCH. It finds that gold has the hedge and safe-haven against inflation and capital markets while Bitcoin has the weak hedge and the weak safe-haven. It shows insignificant effects of inflations of US and Korea on the volatilities of Bitcoin and gold. It also suggests the necessity of clearing of vagueness behind the anonymity for fair and transparent trade through the law application in the absence or fault in law (Lucken im Recht). following the spirit of the living constitution (lebendige gutes Recht oder Vorschrift). The relevant institutions are hoped to be given some of obligations such as registration, minimum required capital. report, disclosure, explanation, compliance and governance with autonomous corresponding rights. The study also suggests the reestablishment of the relevant financial law and taxation law. The hedge would not be successfully accomplished without the vigilant cautions of investors.

• The Korean Journal of Financial Management
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• v.22 no.2
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• pp.213-226
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• 2005

Adverse selection is a heavily scrutinized subject within the financial intermediary industry. Consensus is reached regarding its effect on the loan interest rate. Despite the similar features of financial service offered by the credit card, we still have controversy regarding credit card interest rate on how is adverse selection incurred with the change of interest rate. Thus, this paper explores how does the adverse selection, if ever, take place and affect the credit card interest rate. Information asymmetry regarding the credit card users' type represented by the default probability is assumed. The users are assumed to be rational in that they want to minimize the per unit dollar expense associated with the commercial transaction and financing between the two typical payment methods, cash and credit card. Suppliers, i.e. credit card companies, would like to maximize their profit and would be better off with more pervasive use of credit cards over the cash. Then we could show that the increasing credit card interest rate is subject to the adverse selection, sharing the same tenet with that of the bank loan interest rate proposed by Stiglitz and Weiss. Hence the current theory predicts that credit card market also suffers from adverse selection with increasing interest rate.

• Convergence Security Journal
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• v.12 no.2
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• pp.53-60
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• 2012

Financial institutions keep putting efforts to filling cash into ATMs and branches in order to provide customers with better service. This kind of job usually required an automobile unit to be done, and financial institutions employee perform this task directly or sourcing out to professional security service companies. However, the job has been of ten a target of criminals because it deals with cash. In fact, since 2003, there were several cash truck robberies occurred. This circumstances made the public be aware of the necessity of creative research and the strict management of financial institutions and security companies. However, the existing studies on security service of cash delivery suggest only how to improve the job legally and in operation, and the technological aspect of the improving way has not been studied. Therefore, this study aimed at suggesting an improvement the security service of cash delivery using real-time binary CDMA monitoring for providing better safety service to customers.

• Journal of Digital Convergence
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• v.17 no.3
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• pp.215-220
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• 2019

The block chain technology is a technique that prevents manipulation of data and ensures integrity and reliability. Ethereum is building a smart contract environment as a type of encryptionenabled system based on block chains. Smart contracts can be implemented when conditions are met, thus increasing confidence in digital data. However, smart contracts that are being tried in various ways are not covered by information security and personal information protection. The structure in which the network participant can view the open transaction ledger is exposed to data or personal information listed in the block chain. In this study, it is possible to manage the data of personal information recorded in the block chain directly. This study is protected personal information by preventing the exposure of personal information and by executing time code, it is possible to erase recorded information after a certain period of time has elapsed. Based on the proposed system in the future, it is necessary to study the additional management techniques of unknown code defects or personal information protection.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.50-60
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• 2009

Recently, the traffic card is gradually utilized and its several supplementary services have been significantly developed. Particularly, since it is possible to pay fees for buses, taxies, subways, parking and tollgates with only one traffic card, new payment method for economically processing has been focused. This paper presents a new receipt management system which allows possibly paying with several digital cards through PC interfacing terminals. The proposed system is mainly composed of three parts: terminals, middleware, and management servers. A terminal part includes processing module for payment/charging and credit/check/debit cards, etc and its operation is fulfilled through a middleware part. A main task of a middleware part is to connect a terminal part to managing servers through middleware applications. Additionally, processing of several receipt items and monitoring of the terminals to product statistical reports based on the processed result are carried out in the middleware. A management sever part is accomplished for collecting all of transaction histories against users and charging items over allowed province and managing statistical information. The proposed system is currently utilized in the Nam-GU district office and the Nam-GU district health center, Busan, S. Korea, respectively for testing its effectiveness. We conclude from this demonstration that the system is more useful and efficient than the previous processing method especially in that variable payment ways are provided and consumption burden is reduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.503-514
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• 2019

This paper proposes a blockchain-based urban service-operation model that can enhance usability by integrating several data-driven services operated in a city. In the proposed model, in order to encourage the participation of service users, the providers of data and values that can be consumed and utilized by each service acquire incentives, and consumers can use various services by paying the incentives. In this way, the proposed service model provides a structure in which various services can be interworked within the incentive system. The characteristics of blockchain technology can also guarantee service operation and management transparency. In addition, in this paper, by establishing and operating a prototype, the efficiency and operability of the proposed model are verified. As a result, three implemented data-driven urban management services are organically inter-compatible based on the concept of the proposed integrated incentive system. In the future, the proposed service model can be applied as an elemental technology of urban operational and management architectures based on citizen participation using local currency, and by cooperating with local economic revitalization projects of interest to many local governments. It is expected that the expansion of the blockchain technology area will also be possible through convergence with smart city services.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.2
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• pp.303-310
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• 2018

Bitcoin (BTC) is a cryptocurrency proposed by Satoshi Nakamoto in 2009. Bitcoin makes its transactions with no central authorities. This decentralization is accomplished with its mining, which is an operation that makes people compete to solve math puzzles to include new transactions into block, and eventually block chains (ledger) of bitcoin. Because miners need to solve a complex puzzles, they need a lot of computing resources. In return for miners' resources, bitcoin network gives newly minted bitcoins as a reward to miners when they succeed in mining. To prevent inflation, the reward is halved every 4 years. For example, in 2009 block reward was 50 BTC, but today, the block reward is 12.5 BTC. On the other hands, exchange rate for bitcoin and Korean Won (KRW) changed drastically from 924,000 KRW/BTC (January 12th, 2017) to 16,103,306 KRW/BTC (December 10th, 2017), which made mining more attractive. However, there are no rigorous researches on the profitability of bitcoin mining. In this paper, we evaluate the profitability of bitcoin mining.