• 한국산학기술학회논문지
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• 제5권4호
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• pp.298-302
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• 2004

디지털 콘텐츠의 내용이 다양해지고 유통 구조가 복잡해짐으로 인하여 발생할 수 있는 문제들을 해결하기 위한 방안으로 모바일 환경에서 디지털 콘텐츠를 유통하는 전자상거래 모델을 제안하였다. 무선 환경에서의 온라인 유통 과정은 기존의 오프라인이나 유선 네트워크와는 다른 요소들이 많이 포함되어 있다. 더구나 디지털 저작물인 멀티미디어 콘텐츠는 쉽고 빠르게 불법 복제되고 전파될 수 있다. 이러한 환경 하에서 디지털 콘텐츠의 저작권과 관련된 당사자들의 권리와 이익을 보호할 수 있는 체계가 필요하다. 본 논문에서는 멀티미디어 유통 프레임워크인 MPEG-21에 기반 하여 무선 환경에서의 콘텐츠 유통 전자상거래 프레임워크를 제안하였다. 이 모델은 디지털 저작권 관리 시스템에 적용되어 전자상거래 시장에서 온라인 유통에 있어서 거래 당사자들 사이의 상호 권리 침해 방지를 위한 방법으로 활용될 수 있다.

• Journal of Multimedia Information System
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• 제8권3호
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• pp.197-202
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• 2021

Bitcoin and blockchain are often making headlines not only on TV or media but also among the public in today's society. These technologies have been developed after the risk of the centralized financial system came to the fore during the 2007 global financial crisis. Since then, an anonymous inventor called Satoshi Nakamoto penned the bitcoin white paper where a blockchain-based reference implementation was introduced. Bitcoin was able to achieve unprecedented growth by positioning itself as one of the top global currencies in terms of market capitalization after five years since its development. The pace of Vietnam's economic development is notably fast among Asian nations, while the nation was expected to be a Southeast Asian blockchain hub but they have banned virtual currency trading recently. However, they've also designated the State Bank of Vietnam (SBV) as a responsible agency for the research of blockchain-based cryptocurrencies, the construction of a service ecosystem, and their test operations. The fast-growing economy, increasing number of smartphone users, and the Vietnam government's support policies for startups substantiate these efforts. Therefore, this paper attempts to study the current status of Vietnam's blockchain technology that has been considered to be the center of blockchain systems right behind Singapore, and its implications for Korean companies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.4212-4226
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• 2019

In this paper, a design and implementation for direct deal distribution platform is proposed to bypass the complex traditional distribution structure of agricultural market, as one of the fields where distribution patterns have changed. In the case of domestic agricultural distribution, demand and supply are unstable since the sales market is excessively concentrated in the designated wholesale market. Besides sales must go through multiple stages of distribution leading to problems in freshness and stability of agricultural products and downward pressure on profit margins for producers. To solve the above mentioned issues, we propose a cloud service convergence direct deal distribution platform based on asynchronous-driven Node.js. The proposed platform can facilitate a variety of direct trading functions and also access to visualization information related to agricultural products, which may increase user confidence at an intermediary-free direct transactions platform. First, we describe the requirements of intermediary-free direct transactions of agricultural products and transaction entities. Next the database structure and transaction functions are designed and then implemented according to those requirements. Finally, an API based cloud convergence service structure is designed to provide the analyzed information to ensure a trustworthy system.

• 산업경영시스템학회지
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• 제41권4호
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• pp.81-90
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• 2018

Modern investment theory has empirically proved that stock returns can be explained by several factors such as market risk, firm size, and book-to-market ratio. Other unknown factors affecting stock returns are also believed to still exist yet to be found. We believe that one of such factors is the operational efficiency of firms in transforming inputs to outputs, considering the fact that operations is a fundamental and primary function of any type of businesses. To support this belief, this study intends to empirically study the relationship between firm efficiency and stock price performance. Firm efficiency is measured using data envelopment analysis (DEA) with inputs and outputs obtained from financial statements. We employ cross-efficiency evaluation to enhance the discrimination power of DEA with a secondary objective function of aggressive formulation. Using the CAPM-based performance regression model, we test the performance of equally weighted portfolios of different sizes selected based upon DEA cross-efficiency scores along with a buy & hold trading strategy. For the empirical test, we collect financial data of domestic firms listed in KOSPI over the period of 2000~2016 from well-known financial databases. As a result, we find that the porfolios with highly efficient firms included outperform the benchmark market portfolio after controlling for the market risk, which indicates that firm efficiency plays a important role in explaining stock returns.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5555-5567
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• 2018

State-of-art instance segmentation networks are successful at generating 2D segmentation mask for region proposals with highest classification score, yet 3D object segmentation task is limited to geocentric embedding or detector of Sliding Shapes. To this end, we propose an amodal 3D instance segmentation network called A3IS-CNN, which extends the detector of Deep Sliding Shapes to amodal 3D instance segmentation by adding a new branch of 3D ConvNet called A3IS-branch. The A3IS-branch which takes 3D amodal ROI as input and 3D semantic instances as output is a fully convolution network(FCN) sharing convolutional layers with existing 3d RPN which takes 3D scene as input and 3D amodal proposals as output. For two branches share computation with each other, our 3D instance segmentation network adds only a small overhead of 0.25 fps to Deep Sliding Shapes, trading off accurate detection and point-to-point segmentation of instances. Experiments show that our 3D instance segmentation network achieves at least 10% to 50% improvement over the state-of-art network in running time, and outperforms the state-of-art 3D detectors by at least 16.1 AP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1481-1501
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• 2019

In opportunistic network, the behavior of a node is autonomous and has social attributes such as selfishness.If a node wants to forward information to another node, it is bound to be limited by the node's own resources such as cache, power, and energy.Therefore, in the process of communication, some nodes do not help to forward information of other nodes because of their selfish behavior. This will lead to the inability to complete cooperation, greatly reduce the success rate of message transmission, increase network delay, and affect the overall network performance. This article proposes a hybrid incentive mechanism (Mim) based on the Reputation mechanism and the Credit mechanism.The selfishness model, energy model (The energy in the article exists in the form of electricity) and transaction model constitute our Mim mechanism. The Mim classifies the selfishness of nodes and constantly pay attention to changes in node energy, and manage the wealth of both sides of the node by introducing the Central Money Management Center. By calculating the selfishness of the node, the currency trading model is used to differentiate pricing of the node's services. Simulation results show that by using the Mim, the information delivery rate in the network and the fairness of node transactions are improved. At the same time, it also greatly increases the average life of the network.

• Journal of Information Processing Systems
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• 제18권5호
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• pp.637-649
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• 2022

Investors aim to increase their profitability by investing in the stock market. An adroit strategy for minimizing related risk lies through diversifying portfolio operationalization. In this paper, we propose a six-step stocks portfolio selection model. This model is based on data mining clustering techniques that reflect the ensuing impact of the political, economic, legal, and corporate governance in Mongolia. As a dataset, we have selected stock exchange trading price, financial statements, and operational reports of top-20 highly capitalized stocks that were traded at the Mongolian Stock Exchange from 2013 to 2017. In order to cluster the stock returns and risks, we have used k-means clustering techniques. We have combined both k-means clustering with Markowitz's portfolio theory to create an optimal and efficient portfolio. We constructed an efficient frontier, creating 15 portfolios, and computed the weight of stocks in each portfolio. From these portfolio options, the investor is given a choice to choose any one option.

• Advances in Energy Research
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• 제8권4호
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• pp.243-252
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• 2022

The hybrid wind-solar energy concept has a big influence on the spread of wind and solar power projects in India since it combines the benefits of both industries while also providing extra benefits such as resource sharing such as land, infrastructure, and power evacuation systems. Furthermore, while the hybrid policy may reduce certain barriers to the installation of wind and solar energy in India, there are still some issues that must be resolved rapidly in order to ensure a sustainable installation. According to the study's findings, the installation of wind and solar power plants is significantly influenced by energy policy. The wind-solar hybrid energy strategy will also be crucial in the near future for growing the usage of renewable energy sources. Aside from that, the establishment of Green Energy Open Access (GEOA) and the restart of the trading of Renewable Energy Certificates (REC) would promote the quick deployment of standalone and hybrid renewable power projects throughout the nation, enabling it to reach 500 GW of installed non-fossil energy capacity by 2030.

• 문화기술의 융합
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• 제9권4호
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• pp.529-536
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• 2023

한국의 중고거래 시장은 꾸준한 성장을 보이고 있지만, 중고거래 사기의 발생 건수와 피해 금액도 함께 늘어나고 있다. 2021년 기준 중고거래 시장 규모는 24조원이지만 동시에 사기 피해 금액은 3,606억 원에 달한다. 중고거래 플랫폼은 개인 간 거래 사기를 방지하기 위해 안전거래 결제 시스템을 마련했다. 그러나 안전결제 시스템을 악용한 신종 사기 수법이 생겨나고 있어 중고거래 안전결제도 사기로부터 안전하다고 볼 수 없다. 이에 본 연구는 텍스트마이닝을 활용하여 중고거래 안전결제 서비스의 사기 방지를 위해 생긴 안전결제 시스템의 실태를 파악하고, 이를 텍스트마이닝과 네트워크 분석으로 분석하여 안전결제 시스템의 개선 방안을 제안한다.

• Journal of Information Processing Systems
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• 제20권1호
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• pp.85-92
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• 2024

In recent years, Bitcoin and Ethereum have witnessed a surge in trading activity, driven by venture capital investment and funding through initial coin offerings (ICOs) and initial exchange offerings (IEOs). This heightened interest has led to kickstarting a vibrant ecosystem for blockchain development. The total number of cryptocurrencies listed on CoinMarketCap.com has reached 2,274 highlights how dynamic and wide blockchain development landscape has grown. In blockchain development, new blockchain projects are being created by forking blockchains inspired by major cryptocurrencies such as Bitcoin and Ethereum. These projects aim to address the perceived shortcomings and improve existing technologies. Altcoins, representing these alternative cryptocurrencies, are an ongoing industry effort to improve performance and security with enhancement proposals such as Bitcoin Improvement Proposals (BIP), Ethereum Improvement Proposals (EIP), and EOSIO Enhancement Proposals (EEP). With competitive attempts to improve blockchain performance and security, an ongoing performance race between various blockchains has taken shape, each claiming its own performance advantages. In this paper, we describe the transactions contained in the blocks of each representative blockchain, and find the factors that affect the transactions per second (TPS) through transaction processing and block generation processes, and suggest their relationship with scalability.