• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.497-501
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• 2001

Unbundled power quality service is paid much attention under the circumstances of deregulation and diversification of needs of customers for quality and price of electric power. Moreover, distributed generators (DGs) such as photovoltaic generations and wind turbines will be introduced to distribution system more and more, and reverse flow of active power has possibility to cause new problems in the distribution system such as voltage rise of distribution line and protection problem. Flexible, Reliable and Intelligent Electrical eNergy Delivery System, which is called FRIENDS, has been proposed as one of promising distribution system for such requirements, and intensive studies are under way. One of features of the system is introducing Quality Control Center (QCC) into the system for unbundled power quality service and easy installation of DGs. Two types of QCCs for such purposes are proposed, and simulation results are shown in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.12
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• pp.981-989
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• 1990

Thos paper summarized previously proposed several public key distribution systems and proposes a new public key distribution system to generate an common secret conference key for public key distribution systems three or more user. The now system is based on discrete exponentiation, that is all operations involve reduction modulo p for large prime p and we study some novel characteristics for computins multiplicative inverse in GF(p). We use one-way communication to distribute work keys, while the other uses two-way communication. The security of the new system is based on the difficulty of determining logarithms in a finite field GF(p) and stronger than Diffie-Hellman public key distribution system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.39-44
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• 2005

This paper is about the new distribution system of the electric customer inside. The power loss in the distribution system of the customer is disregarded and rarely managed so for. But, economically, this loss is not small quantity to ignore. So, in this paper, we suggest that the new distribution system of the electric customer inside by simply changing the locations of power transformer and other power facilities which is located inside of the customer. And we also show that the power loss is decreased with this systematic changing by approximated calculation.

• Transactions on Electrical and Electronic Materials
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• v.18 no.3
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• pp.169-175
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• 2017

A safe and reliable protection system in distribution networks, specifically, those hosting distribution generation units, needs a robust over-current protection scheme. To avoid unintentional DG disconnection during fault conditions, a protection system should operate quickly and selectively. Therefore, to achieve this aim, satisfying coordination constraints are important for any protection scheme in distribution networks; these pose a challenging task in interconnected and large-scale networks. In this paper, a new coordination strategy, based on the same non-standard time-current curve for all relays, in order to find optimal coordination of directional over-current relays, is proposed. The main aim is to reduce violations, especially miscoordination between pair relays. Besides this, the overall time of operation of relays during primary and backup operations should be minimized concurrently. This work is being tackled based on genetic algorithms and motivated by the heuristic algorithm. For the numerical analysis, to show the superiority of this coordination strategy, the IEEE 30-bus test system, with a mesh structure and supplemented with distributed generation, is put under extensive simulations, and the obtained results are discussed in depth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.541-542
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• 2007

The paper also introduces a new Distribution Class ground lead disconnector design that not only extends the claimable detonation range well below the 20 amps specified in industry standards, but is very durable when exposed to severe arrester durability tests. Finally. this paper shows how this next generation disconnector interacts with the connected arrester to improve the overvoltage withstand capability of the arrester assembly. The interaction of the disconnector grading capacitor with the series-connected arrester metal oxide disc elements actually improves the arrester assembly temporary overvoltage withstand capability, making the design less vulnerable to TOV failures. Since the vast majority of distribution class arresters are sold domestically with ground lead disconnectors, this design improvement in the disconnector to improve detonation reliability also translates into a significantly improved distribution class arrester design.

• New & Renewable Energy
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• v.5 no.4
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• pp.11-18
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• 2009

Wind energy resources are recently considered as an important power generation alternative in the future. The fact that the investment of wind turbine installation continues to increase has motivated a need to develop more widely applicable methodologies for evaluating the actual benefits of adding wind turbines to conventional generating systems. This study is aiming to estimate the future wind resources with various estimation methods. The wind power is calculated at the hub height 75m of 800KW and 1,500KW wind turbines in Wolryong site, Jeju island, South Korea. Three equations - logarithmic, profile, and power law methods are applied for the accurate prediction of wind profile. In addition, yearly wind power can be calculated by using Weibull & Rayleigh distribution. It is found that predicted wind speed is highly affected by friction velocity, atmospheric stability, and averaged roughness length. It is concluded that Rayleigh distribution provides greater power generation than the Weibull distribution, especially for low wind-speed condition.

• Wind and Structures
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• v.19 no.4
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• pp.371-387
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• 2014

Probability plotting positions are popular and used as the basis for distribution fitting and for inspecting the quality of the fit because of its simplicity. The plotting positions that lead to excellent approximation to the mean of the order statistics should be used if the objective of the fitting is to estimate quantiles. Since the mean depends on the sample size and is not amenable for simple to use closed form solution, many plotting positions have been presented in the literature, including a new plotting position that is derived based on the weighted least-squares method. In this study, the accuracy of using the new plotting position to fit the Gumbel distribution for estimating quantiles is assessed. Also, plotting positions derived by fitting the mean of the order statistics for all ranks is proposed, and an approximation to the covariance of the order statistics for the Gumbel (and Weibull) variate is given. Relative bias and root-mean-square-error of the estimated quantiles by using the proposed plotting position are shown. The use of the proposed plotting position to estimate the quantiles of annual maximum wind speed is illustrated.

• Journal of Hydrogen and New Energy
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• v.34 no.4
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• pp.369-380
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• 2023

There is no clear standard for estimating the power distribution of fuel cells and batteries to meet the required power in hydrogen electric vehicles. In this study, a hydrogen electric vehicle simulation model equipped with a vehicle electric component model including a fuel cell system was built, and a power distribution strategy between fuel cells and batteries was established. The power distribution model was operated through two control strategies using step control and fuzzy control, and each control strategy was evaluated through data derived from the simulation. As a result of evaluation through the behavior data of state of charge, fuel cell current and balance of plant, fuzzy control was evaluated as a proper strategy in terms of control stability and durability.

• Journal of Distribution Science
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• v.21 no.4
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• pp.69-80
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• 2023

Purpose: In the landscape of global challenges, the adoption of new technologies and the implementation of intellectual capital are seen as the main vehicles to enhance banking operations. Inspired by this issue, our study is to discover the effect of technological investments and intellectual capital on one of the most important dimensions of banking operations, namely deposit intermediation. Research design, data and methodology: To tackle this concern, we utilize the data of 12 banks from 2011 to 2020 in Vietnam, and perform the multivariate regression analysis as well as provide different robustness tests. Results: Our empirical analysis demonstrates that a surge in technological expenditures would foster distribution of deposit intermediation of banks. Also, the blend of technology spending and intellectual capital plays a key role in boosting this function of banks. Conclusions: The study would bring one of new evidence for bank managers and national authorities in Vietnam, where has undergone the completely reform period in banking system. Accordingly, technological innovation and intellectual capital should be taken into consideration when managers and regulators build business strategies and related policies. The findings are also useful for nations bearing a close resemblance to Vietnamese financial system.

• Journal of Distribution Science
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• v.22 no.8
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• pp.55-63
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• 2024

Purpose: This study focuses on the golden banana (Kluai Hom Thong) from the Ban Khok Banana Community Enterprise Group in Sang Khom District, Udon Thani Province, Thailand. Despite its potential as an export crop and minimal disease or insect management issues, the group's products struggled to reach international markets due to lack of marketing opportunities, distribution channels, and proper packaging. The research aims to analyze and develop packaging and logos to test market potential for the group's products. Research design, data and methodology: Data was collected through questionnaires developed in conjunction with three printing and packaging design experts. Market testing involved 100 randomly sampled consumers of the group's products. Results: The new packaging design was perceived as more international, modern, and suitable as a souvenir for adults. Conclusions: Integrating ethnic elements and local materials into packaging design can enhance product appeal. For example, creating cloth bags from fabric scraps for carrying local woven products can impress consumers. This approach could help overcome market barriers and improve prospects for golden banana products in international markets while maintaining the intact ecosystem and environment of the production area. The study highlights the importance of effective packaging and branding in addressing market access challenges for local agricultural enterprises, potentially opening new opportunities for community-based businesses.