• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.848-849
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• 2005

• Electronics and Telecommunications Trends
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• v.36 no.3
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• pp.53-64
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• 2021

As the 5G service market is expected to grow rapidly, the development of high-power, high-efficiency power amplifiers for the 5G communication infrastructure is indispensable. Gallium nitride (GaN) is attracting great interest as a key device in power devices and integrated circuits due to its wide bandgap, high carrier concentration, high electron mobility, and high-power saturation characteristics. In this study, we investigate the technology trends of Ka-band GaN radio frequency (RF) power devices and integrated circuits for operation in the millimeter-wave band of recent 5G mobile communication services. We review the characteristics of GaN RF high electron mobility transistor (HEMT) devices to implement power amplifiers operating at frequencies around 28 GHz and compare the technology of foreign companies with the device characteristics currently developed by the Electronics and Telecommunication Research Institute (ETRI). In addition, the characteristics of Ka-band GaN monolithic microwave integrated circuit (MMIC) power amplifiers manufactured using various GaN HEMT device technologies are reviewed by comparing characteristics such as frequency band, output power, and output power density of integrated circuits. In addition, by comparing the performance of the power amplifier developed by ETRI, the current status and future direction of domestic GaN power devices and integrated circuit technology will be discussed.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.2
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• pp.329-333
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• 2021

V2G (Vehicle to Grid) technology for an EV (Electric Vehicle) has been assumed as so promising in a near future for its useful energy resource concept but still yet to be developed around the world for specific service purposes through various R&BD projects. Basically, V2G returns power stored in vehicle at a cheaper or unused time to the grid at more expensive or highly peaked time, and is accordingly supposed to provide such roles like peak shaving or load levelling according to customer load curve, frequency regulation or ancillary reserves, and balancing power fluctuation to grid from the weather-sensitive renewable sources like wind or solar generations. However, it has recently been debated over its prominent usage as diffusing EVs and the required charging/discharging infrastructure, partially for its addition of EV ownership costs with more frequent charging/discharging events and user inconvenience with a relative long-time participation in the previously engaged V2G program. This study suggests that a Korean DR (Demand Response) service integrated V2G system especially based upon a dynamic charge/pause/discharge scheme newly proposed to ISO/IEC 15118 rev. 2 can deal with these concerns with more profitable business model, while fully making up for the additional component (ex. battery) and service costs. It also indicates that the optimum economic, environmental, and grid impacts can be simulated for this V2G-DR service particularly designed for EV aggregators (V2G service providers) by proposing a specific V2G engagement program for the mediated DR service providers and the distributed EV owners.

• Journal of applied mathematics & informatics
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• v.35 no.1_2
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• pp.25-32
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• 2017

Let G be a graph and k is a positive integer. Hammack and Livesay in [The inner power of a graph, Ars Math. Contemp., 3 (2010), no. 2, 193-199] introduced a new graph operation $G^{(k)}$, called the $k^{th}$ inner power of G. In this paper, it is proved that if G is bipartite then $G^{(2)}$ has exactly three components such that one of them is bipartite and two others are isomorphic. As a consequence the edge frustration index of $G^{(2)}$ is computed based on the same values as for the original graph G. We also compute the first and second Zagreb indices and coindices of $G^{(2)}$.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.758-760
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• 1998

This paper provides the results of performance investigation of gas insulated switches(G/S) for distribution power system. In order to investigate anti-contamination capability of G/S we carried out electrical tests and material analysis on the body of G/S and it's accessories. Through this experiment we found out the lead cable of G/S had not anti-contamination capability and G/S had insufficient interval between each phase. In order to improve the performance of G/S for heavy contamination area it is indispensable to replace the lead cable to the new cable which has anti-contamination ability.

• Journal of applied mathematics & informatics
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• v.42 no.2
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• pp.445-456
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• 2024

A power cordial labeling of a graph G = (V (G), E(G)) is a bijection f : V (G) → {1, 2, ..., |V (G)|} such that an edge e = uv is assigned the label 1 if f(u) = (f(v))ⁿ or f(v) = (f(u))ⁿ, for some n ∈ ℕ ∪ {0} {0} and the label 0 otherwise, then the number of edges labeled with 0 and the number of edges labeled with 1 differ by at most 1. In this paper, we study power cordial labeling and investigate power cordial labeling for some standard graph families.

• Journal of Information Technology Services
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• v.18 no.3
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• pp.53-74
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• 2019

In this paper, a theoretical measurement model for comparing cultural power of nations as a form of national power is built and applied to the G20 nations. The measurement model is drawn from the literature of the state theories regarding culture, theories of epistemology, and debates about the sources of national power. Taking the multiple indicator approach, indicators reflecting diverse aspects of cultural power are developed are developed. Examined with empirical data, this model is proved as appropriate as a tool for measuring and comparing the cultural power of nations. Diverse aspects of the cultural power of the G20 nations are ranked and interesting points regarding the state and potential of Korean culture and her cultural governance in these respects are elaborated. The overall ranking of the cultural power of Korea is found as the $11^{th}$ while the U.S., U.K. and France respectively as the $1^{st}$, the $2^{nd}$, and the $3^{rd}$. The U.S. is ranked as the 1st in all three aspects of the cultural power of nation: cultural attractiveness, efforts to enhance the national cultural power, and cultural base of a nation. Korea is ranked as $14^{th}$, $11^{th}$, and $6^{th}$ respectively in these three respects of the national cultural power. Based upon typological analysis of the cultural power of Korea, it is found that Korea belongs to Type III. Trying to move eventually toward Type I state via Type II is suggested as a strategy movement for future cultural governance by Korean government and people to enhance her national cultural power.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.1
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• pp.55-68
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• 2001

This paper presents a new ALU architecture to minimize glitching power consumption which is appeared in the conventional one with P(carry propagation)/G(carry generation) blocks. In general, A lot of glitches generated once are propagating into the next stage of circuits to make unnecessary power dissipation. Therefore, a new ALU architecture which removes the glitches at the output of P/G blocks is presented in this paper. If a lot of glitches at the output of P/G blocks are removed, then the signal transitions caused by glitches are reduced in the sum generation block and hence power consumption is also reduced. A latch is inserted into the conventional P/G blocks to remove the glitches at the output of P/G blocks. Latch enable signal can make a role in eliminating a lot of glitches at the P/G's outputs by controlling output enable time. Experimental results from HSPICE simulations with implementing 16-b ALU show 28% reduction in glitching power consumption with negligible delay penalty.

• Journal of applied mathematics & informatics
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• v.41 no.3
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• pp.615-631
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• 2023

A power cordial labeling of a graph G = (V (G), E(G)) is a bijection f : V (G) → {1, 2, ..., |V (G)|} such that an edge e = uv is assigned the label 1 if f(u) = (f(v))ⁿ or f(v) = (f(u))ⁿ, For some n ∈ ℕ ∪ {0} and the label 0 otherwise, then the number of edges labeled with 0 and the number of edges labeled with 1 differ by at most 1. In this paper, we investigate power cordial labeling for helm graph, flower graph, gear graph, fan graph and jewel graph as well as larger graphs obtained from star and bistar using graph operations.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2008.05a
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• pp.281-282
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• 2008