• Journal of Communications and Networks
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• 제8권4호
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• pp.442-450
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• 2006

Inter-operability between heterogeneous radio access technologies (RATs), in the sense of seamless vertical han-dover (VHO) support with common radio resource management (CRRM) functionalities, has recently attracted a significant research attention and has become a prominent issue in standardization fora. In this paper, we formulate the problem of load balancing between cooperative RAT's as a mathematical program and by trading off a pre-defined delay tolerance per request we propose a vertical handover batch processing (VHBP) scheme. To quantify the performance of the proposed VHBP scheme we compare it with a baseline processing scheme, where each VHO request is processed independently under a number of different network scenarios. Numerical investigations reveal significant net benefits of the proposed scheme compared with the baseline, both in terms of achieved load balancing levels but also with regard to the acceptance rate of the VHO requests.

• Asia pacific journal of information systems
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• 제16권3호
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• pp.1-27
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• 2006

In supply chains, collaboration between buyer and supplier can improve firms' ability of supply chains to their objectives and competitive advantages. A key factor in collaboration in supply chain is to identify buyer relationships and supply relationships as antecedents of the factor collaboration. We analyzed data collected from buyers and suppliers sampled from a mobile networks industry in Korea and found that the level of collaboration comes from strong relationships between two parties and the collaboration enhances the supply chain performances. However, buyer relationships and supplier relationships have indirect impacts on trading partners' performance through collaboration whereas both have direct impacts on one's performance. Therefore to enhance supply chain performances, supplier's operational efficiency and buyer satisfaction, firms of buyers and suppliers should consider pursuing practical and substantial collaboration along with buyer-supplier relationships.

• Acta Via Serica
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• 제8권2호
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• pp.95-124
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• 2023

Over the past 30 years, intense archaeological research has revealed a great increase in regional and transregional object mobility across the South China Sea during its Iron Age (500 BCE to 500 CE). Some objects had moved from a long distance: intaglios, seals, fine ceramic, glass containers, and gold coins of Mediterranean origin; and large bronzes, mirrors, and lacquerware connected to central East Asia. This evidence has given rise to larger-scale explanations, among which the most prominent has been the growth of (maritime) Silk Road trade. Scholars are divided as to whether the Silk Road is a suitable concept, with some emphasizing its orientalist overtones and colonial baggage and others finding it useful for the investigation of interregional networks trading in silk and other commodities. This paper explores how productive the Silk Road concept or metaphor really is for understanding transregional connectivity and social change in Iron Age Southeast Asia.

• ETRI Journal
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• 제44권6호
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• pp.945-954
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• 2022

The 5G mobile network is promising to handle the dynamic traffic demands of user equipment (UE). Unmanned aerial vehicles (UAVs) equipped with wireless transceivers can act as flying base stations in heterogeneous networks to ensure the quality of service of UE. However, it is challenging to efficiently allocate limited bandwidth to UE due to dynamic traffic demands and low network coverage. In this study, a blockchain-enabled bandwidth allocation framework is proposed for secure bandwidth trading. Furthermore, the proposed framework is based on the Cournot oligopoly game theoretical model to provide the optimal solution; that is, bandwidth is allocated to different UE based on the available bandwidth at UAV-assisted-based stations (UBSs) with optimal profit. The Cournot oligopoly game is performed between UBSs and cellular base stations (CBSs). Utility functions for both UBSs and CBSs are introduced on the basis of the available bandwidth, total demand of CSBs, and cost of providing cellular services. The proposed framework prevents security attacks and maximizes the utility functions of UBSs and CBSs.

• 정보학연구
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• 제8권4호
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• pp.119-140
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• 2005

The purpose of this article is to study on the electronic bill of lading in the electronic trade era. The term 'electronic trade' means all or part of any such trade as implemented by means of apparatus having the information processing capability, such as a computer, and networks of information and communications. The introduction of an electronic bill of lading has long been considered essential by the members of the international trading community as a key means of reducing its costly reliance on paper.

• Journal of the Korean Data and Information Science Society
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• 제14권4호
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• pp.845-852
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• 2003

Forecasting exchange rate movements is a challenging task since exchange rates impact world economy and determine value of international investments. In particular, Korean-U.S. exchange rate behavior is very important because of strong Korean and U.S. trading relationship. Neural networks models have been used for short-term prediction of exchange rate movements. Least squares support vector machine (LS-SVM) is used widely in real-world regression tasks. This paper describes the use of LS-SVM for short-term and long-term prediction of Korean-U.S. exchange rate.

• Management Science and Financial Engineering
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• 제11권3호
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• pp.1-17
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• 2005

Agent technology has been widely applied in today's electronic business, such as mobile agents, multi-agent information systems, etc. In particular, multi-agent systems have been applied as powerful simulation tools to study complex business networks composed of various self-interested trading firms and/or human beings. In this paper, we build an integrated model that consists of a multi-agent B2C market model and a B2B trade network model, and incorporate more reality than much of prior work. Then with this model, we carry out experimental studies on two different strategies that are common in electronic business - 'loyal' strategy (retailers try to build stable cooperation with suppiers to ensure material supply) and 'cost-saving' strategy (retailers try to reduce cost by choosing suppliers with lower wholesale price).

• 한국항해항만학회지
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• 제42권2호
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• pp.117-126
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• 2018

Container port is one of the most vital link of the transportation chain that plays an important role in trading with other countries. Having a proper understanding of port operations could change the role of the port from a transportation node to an efficient point in a transportation chain. Development of transportation chains, logistics and progress of these networks have enhanced the sustainable condition and level of transportation. Therefore, evaluating the competitiveness of ports is obligatory for port users to make a decision in investment or exploitation. This paper introduces the use of Fuzzy C-means and TOPSIS for competitiveness comparison among a sample of container terminals in Korea and China and determine how to improve Korean port competitiveness and particularly in Busan port.

• 통합자연과학논문집
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• 제14권2호
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• pp.65-72
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• 2021

This paper discusses on the implementation of blockchain system, specifically the private system for Energy trading purpose. Blockchain is records bundled together in blocks and added to the chain after ledger is generated. All the blocks in the entire networks should be same contents and also only the permitted nodes can join the chain in the private blockchain system, thus not that same block and permitted nodes cannot be accepted in terms of proof-of-work phase. We implement the all stages which are necessary to process blockchain system. After coding the whole process, we test and conclude that the system is correctly working in terms of the functions implemented.

• 한국콘텐츠학회논문지
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• 제12권2호
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• pp.472-482
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• 2012

주식시장에는 많은 투자자들이 참여하고 있으며 점점 더 많은 사람이 주식투자에 관심을 가지고 있다. 주식시장에서 위험을 회피하고 수익을 얻기 위해서는 다양한 정보를 바탕으로 정확한 의사결정을 해야한다. 즉 수익을 얻을 수 있는 종목 선택, 적절한 매수-매도 가격의 결정, 그리고 적절한 보유기간 등을 결정해야 한다. 본 논문에서는 개인 주식 투자자의 의사결정 지원을 위한 데이터마이닝 도구를 제안한다. 즉, 개인 투자자가 직접 기계학습 방법을 적용하여 주가예측 모델을 생성할 수 있게 하고, 적절한 매수-매도 가격과 보유기간 등을 결정하는 것을 도와주는 도구를 제안한다. 제안하는 도구는 과거 데이터를 이용하여 투자자 자신의 성향에 맞는 투자에서의 의사결정을 할 수 있도록 지원하는 도구로서 주가데이터 관리, 기계학습 적용을 통한 주가예측 모델 생성, 투자 시뮬레이션 등의 기능을 제공한다. 사용자는 스스로 주가에 영향을 미칠 수 있다고 판단하는 기술적 지표를 선정하고 이를 이용하여 주가예측 모델을 만들고 테스트 할 수 있으며, 적절한 예측모델을 적용하여 시뮬레이션을 수행해 봄으로써 실제로 어느 정도 수익을 얻을 수 있는지 평가하고 적절한 매매 정책을 수립할 수 있다. 제안하는 도구를 이용하여 주식 투자자는 기존의 감정적 판단에 의한 투자가 아닌 객관적 데이터에 의해 검증을 거친 주가예측 모델과 매매정책에 따라 주식투자를 할 수 있어 이전 보다 나은 수익을 기대할 수 있다.