• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.315-316
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• 2016

This paper proposes an enhanced distributed generation (DG) unit with an adaptive virtual impedance control approachin order to address the inaccurate reactive power sharing problems. The proposed method can adaptively regulate the DG unit thanks to the equivalent impedance, andthe effect of the mismatch in feeder impedance is compensatedto share the reactive power accurately.The proposed control strategy can be implemented directly without any requirement of pre-knowledge of the feeder impedances. Simulations are performed to validate the effectiveness of the proposed control approach.

• Journal of Environmental Policy
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• v.6 no.3
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• pp.91-114
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• 2007

The cooperative cost sharing scheme for Dust and Sand Storm(DSS) in North East Asia, as suggested in Song and Nagaki(2007), may not be feasible due to possible defection(s) of participating countries. If non-cooperative strategies are more plausible, Nash equilibrium can suggest possible outcomes of the cost sharing game. The result from the continuous strategy model shows that there exists an infinite number of Nash equilibrium such that the summation of investment from each country is always equal to the required budget of the ADS pilot project. It is also discussed that the discrete strategy model points to only 3 Nash equilibria in continuous strategy game outcome and the cooperative game solution may be just one of the infinite equilibria.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3456-3468
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• 1999

Most of previous parallel join algorithms assume a database partition system(DPS), where each database partition is owned by a single processing node. While the DPS is novel in the sense that it can interconnect a large number of nodes and support a geographically distributed environment, it may suffer from poor facility for load balancing and system availability compared to the database sharing system(DSS). In this paper, we propose a dynamic load balancing strategy by exploiting the characteristics of the DSS, and then extend the conventional hash join algorithms to the DSS by using the dynamic load balancing strategy. With simulation studies under a wide variety of system configurations and database workloads, we analyze the effects of the dynamic load balancing strategy and differences in the performances of hash join algorithms in the DSS.

• New & Renewable Energy
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• v.17 no.2
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• pp.9-23
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• 2021

In Korea, various community investment renewable project models are being implemented to increase community acceptance of renewable energy. An important factor for enhancing local acceptance is that renewable energy projects have a positive effect on revitalizing the local economy such as income increase or job creation for residents and local companies. To maximize the local economic effect of large-scale community investment renewable energy projects, this study developed an evaluation index for local economy activation, whose indicators are the local return on investment, local companies' participation, local job creation, regional cooperation, transparency, and governance. Analysis of existing evaluation indicators and current renewable projects, financial analysis, and expert interviews were used in this research. The pilot evaluation determined that, the local economic effect was high in the following order: a fund investment wind project (Gangwon), benefit-sharing wind project (Jeju), and general wind project. In particular, residents' investment amount, the number of participating residents, and the amount and transparency of the regional cooperation fund were key factors to expand the effect of local economy activation. This evaluation index could be used in public bidding for renewable energy projects such as offshore wind zoning areas of local government.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.4
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• pp.37-50
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• 2007

Dramatic development of information technology requires new type of sales strategy to enterprise S/W dealers. That is, one should thoroughly consider diversified types of enterprise S/W and more elaborated consumer needs to establish successful sales strategy. However, various factors that should be considered in establishing enterprise S/W sales strategy are different according to types of enterprise S/W and hard to be managed systematically which led to the current situation where they have not been discussed enough. Therefore, this study introduced the relationship between the factors that affect selection of enterprise S/W using the concept of cognitive map on various enterprise S/W sales cases. Through this process, this study grouped the cognitive maps of similar cases to introduce their characteristics and made this result to be practically useful to enterprise S/W sales strategy.

• Asia Marketing Journal
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• v.17 no.3
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• pp.73-103
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• 2015

According to Resource Dependence theory, an organization's behavior and strategy is affected by external resources. An organization has diverse resources interacting with environment. Because organization cannot focus on all those resources, it concentrates on its critical resources. In market environment, firm responds to other firms by controlling their internal critical resources or manages interdependency with environment to get market share. Thus Firm should choose best behavior and strategy when internal and external resources are change. When new brand enters, incumbents might change their strategy to protect their market share depending on critical value. More precisely, incumbents sharing market with entrant respond, but incumbents having competitive internal resources do not. In this article, we study incumbent's responses to a new brand entry and long-term effect. We show that how incumbents change their price strategy in reaction to the new brand' entry and also show these responses vary depending on interdependency of internal resources and external environments and ownership.

• Information Systems Review
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• v.12 no.1
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• pp.81-105
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• 2010

This research explores the role of personal performance expectation, task-technology fit, perceived rewards, shared vision, usefulness of knowledge sharing, top management support, organization culture, organizational commitment, KMS self-efficacy as antecedents which affect knowledge sharing activity as a consequence and investigates relationships among variables considering characteristics. The results show that members' perceived personal performance expectation, task-technology fit, perceived rewards, shared vision, usefulness of knowledge sharing, top management support, organization culture, organizational commitment, KMS self-efficacy has a positive effect perspectively on knowledge sharing in a organization. Especially, the fact that perceived members' task-technology fit, perceived rewards, usefulness of knowledge sharing is more important than other variables was confirmed. The results of this study, knowledge-sharing activities of the enterprise, members of the organization's business strategy for the activation process is expected to help.

• Journal of the Korea Convergence Society
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• v.9 no.3
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• pp.181-186
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• 2018

Car-sharing services are one of the successful model of sharing economies. The car-sharing service is a kind of car rental service that can pay the cost per minutes, also can makes it easy to book and return by smart phone at any time. Experts predict that the car-sharing services will likely dominate the auto market in the future by reducing the burden on consumers' purchasing cost of car and resolving the environmental issues caused by the vehicle. Therefore, a differentiated service strategy is needed to establish a competitive caching service among these companies. In this study, we surveyed differentiation cases by comparing and analyzing domestic caching companies, And customized service tailored to the situation and effective vehicle type infotainment. As a result of this study, the proposed service method change, customized service provision, and new platform application are expected to be detailed and in depth.

• The KIPS Transactions:PartA
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• v.10A no.4
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• pp.331-338
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• 2003

Cluster is the cost-effective parallel processing environment, and consists of the off-the-shelf computers connected by the computer net works. The characteristics of cluster are the node heterogeneity, the variety of node load, and the variety of network load. Because these characteristics influence the performance of parallel program executions, the load sharing for cluster is important, and by using the proper load sharing strategy, we can reduce the execution time of parallel programs. In this paper, we propose modified GSS algorithm, αGSS. In the proposed load sharing algorithms α GSS, the size of tasks are decided using the BogoMIPS of node. From the result of out experiments, we conclude that the proposed αGSS algorithm is effective in the heterogeneous cluster.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.10
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• pp.5144-5160
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• 2019

Secret sharing is an effective way of protecting secret messages. However, the traditional secret sharing schemes are considered meaningless due to malicious people attention which might raise risks. To overcome the weakness, this paper presents an effective secret sharing scheme with the functionality of cheater identification, based on meaningful QR code. The secret message will be split and concealed in the padding region of cover QR codes with the assistance of Latin square and it can be completely restored when all the involved participants cooperate. The concealing strategy exploits the characteristic of Reed-Solomon (RS) code to ensure the strong robustness of generated QR code pseudo-shares. The meaningful QR code pseudo-shares help to reduce the curious of unrelated persons. Some experiments were done to evaluate the performance of proposed scheme. The results showed that the proposed scheme is feasible, efficient and secure compared to the other existing schemes. It also achieves a higher secret payload and maintains stronger robustness.