• KIPS Transactions on Computer and Communication Systems
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• v.10 no.6
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• pp.173-180
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• 2021

Non Orthogonal Multiple Access (NOMA) is a technology to guarantee the explosively increased Quality of Service(QoS) of users in 5G networks. NOMA can remove the frequent orthogonality in Orthogonal Multiple Access (OMA) while allocating the power differentially to classify user signals. NOMA can guarantee higher communication speed than OMA. However, the NOMA has one disadvantage; it consumes a more energy power when the distance increases. To solve this problem, relay nodes are employed to implement the cooperative NOMA control idea. In a cooperative NOMA network, relay node participations for cooperative communications are essential. In this paper, a new bandwidth allocation scheme is proposed for cooperative NOMA platform. By employing the idea of Vickrey-Clarke-Groves (VCG) mechanism, the proposed scheme can effectively prevent selfishly actions of relay nodes in the cooperative NOMA network. Especially, base stations can pay incentives to relay nodes as much as the contributes of relay nodes. Therefore, the proposed scheme can control the selfish behavior of relay nodes to improve the overall system performance.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.46
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• pp.133-158
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• 2010

Independent guarantee is a creation of the need from the both sides, i.e. the applicant (principal debtor) and the beneficiary (creditor). The former used to have to deposit cash in favor of the beneficiary in case of his default, which laid a burden on his liquidity while the latter still wanted to have the equivalent to cash. Independent guarantee satisfied the both parties by freeing the applicant of a deposit and maintaining the beneficiary's right at the same time. The fact that independent guarantee has three payment mechanisms is not widely known to the public. They are (i) payment on first demand, (ii) payment upon submission of third-party documents, (iii) payment upon submission of an arbitral or court decision. From the applicant's point of view, the order in his favor is (iii), followed by (ii) and (i). As there shouldn't be a case where one party is at a disadvantage against the other, useful insight is being sought for the benefit of the applicant. First, the applicant can offer his intention to provide a payment mechanism (ii) or (iii) rather than (i) if he must deliver it. Second, if the beneficiary still wants to have (i) and the applicant is in a position not to reject it, the latter should thoroughly check any provisions that may work against him later. Third, the applicant could use counterbalancing provisions in underlying contract to cope with protective clauses in the guarantees. Forth, the applicant should review the beneficiary's sincerity to prevent unfair calling risks. The applicant may use an ECA(Export Credit Agency) in his country to which he can transfer not only unfair calling risks, but also political risks. On the other hand, a bank needs to keep the following advice in mind. The foremost important thing for the bank not to forget is that it provides a guarantee as a service provider, not as a responsible party for the feasibility of the project, etc. Credit risk of the applicant should require the greatest attention when issuing a guarantee: the bank should look into the possibility that it can procure immediate reimbursement from its customers after payment to the beneficiary. Second, the applicant's ability to complete the project should be reviewed by checking its track records, techniques and reputation, etc. Third, the bank may also use an ECA to cover the beneficiary's unfair calling risks as well as political risks. In the case of Korea, as Korea Export Insurance Corporation(KEIC) can cover all the risks mentioned above, the bank could use its service called 'Export Bond Insurance.' What's better for the bank is that ECA cover can enhance the bank's asset quality by putting it zero on its risk weighted asset.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.4
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• pp.999-1007
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• 2018

To implement crowdsensing system in reality, trustiness between service provider server and user is necessary. Service provider server could manipulate the evaluation of sensing data to reduce incentive. Moreover, user could send a fake sensing data to get unjust incentive. In this paper, we adopt private blockchain on crowdsensing system, and thus paid incentives and sent data are unmodifiablely recorded. It makes server and users act as watcher of each others. Through adopting smart contract, our system automates sensing data evaluation and opens to users how it works. Finally, we show the feasibility of proposing system with performance evaluation and comparison with other systems.

• International Commerce and Information Review
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• v.17 no.2
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• pp.3-18
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• 2015

This thesis examines the performance and improvement strategy of SWIFTNet TSU's BPO for computerization and suggests the following results: First, the URBPO should be legally complemented, and the SWIFT and banks need to keep improving the systems to meet trade parties' diverse needs. Second, the SWIFTNet TSU's BPO should have an institutionally unified sharing platform with security, stability and convenience. In other words, it is needed to develop services which meet e-payment paradigm and international and regional environments through continued analysis on market changes and flow. Third, in order for the SWIFTNet TSU BPO to evolve into a perfect global system, there should be an innovative payment solution which can meet all trade parties all over the world. For this, technology standardization for a worldwide e-trade payment system is essential. Lastly, based on the results derived from this study, an analysis framework with which more diverse and practical environmental variables can be analyzed should be developed.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.115-131
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• 2011

Out of all the possible actions that can be taken to respond to greenhouse gas reduction, including development of greenhouse gas reduction technology, infrastructure, actions to improve energy saving and efficiency, and offset with carbon emission reductions (CERs), this study shall focus on the investment on CERs. This study will take a look at risks involved with investing in CERs such as UN registration refusal risk and CERs price fluctuation, and will design risk management model which shall be verified. The goal of this paper is to provide optimized CERs investment strategies for different types of investors, such as general trading companies seeking for investment opportunities and financial companies with plans for green products development and investment by preparation for carbon market. It is expected that the global competitiveness of domestic financial companies shall be improved by taking actions on carbon market instead of previous passive response to climate change and that Korea, the number two Carbon Emissions supplier and number one derivatives market in terms of volume, shall be able to lead the worldwide carbon market.