• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2751-2755
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• 2011

The visible vibronic emission spectrum was recorded from the corona discharge of precursor 1,2,3,4-tetramethylbenzene with a large amount of inert carrier gas helium using a pinhole-type glass nozzle coupled with corona excited supersonic expansion. The spectrum showed a series of vibronic bands in the $D_1{\rightarrow}D_0$ electronic transition of jet-cooled benzyl-type radicals formed from the precursor in a corona excitation. The analysis confirmed that two isomeric radicals, 2,3,4- and 2,3,6-trimethylbenzyl radicals, were produced as a result of removal of a hydrogen atom from the methyl group at different substitution positions. For each isomeric product, the electronic transition and a few vibrational mode frequencies were determined in the ground electronic state.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.344-349
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• 2005

In conventional small signal stability analysis, the system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of the state matrix. However, when a system contains switching elements such as FACTS equipments, it becomes a non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is performed by means of eigenvalue analysis of the system's periodic transition matrix based on the discrete system analysis method. In this paper, the RCF (Resistive Companion Form) method is used to analyze the small signal stability of a non-continuous system including switching elements. Applying the RCF method to the differential and integral equations of the power system, generator, controllers and FACTS equipments including switching devices should be modeled in the form of state transition equations. From this state transition matrix, eigenvalues that are mapped into unit circles can be computed precisely.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.329-333
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• 2012

For phase transition method, good record sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, a retention time is very important part for phase-transition. In our past papers, we chose composition of $Ge_1Se_1Te_2$ material to use a Se factor which has good optical sensitivity than conventional Sb. Sb/Ge-Se-Te thin films are fabricated and irradiated with UV light source to investigate a reversible phase change by Sb-doped condition. Because of Sb atoms, the Sb inserted sample showed better performance than conventional one. We should note that this novel one showed another possibility for phase-change random access memory.

• Journal of Distribution Science
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• v.15 no.1
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• pp.83-93
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• 2017

Purpose - After the transition, the development of defense industry in Eastern Europe has been regressed. Recently, they have internationally recognized that new products have been exported and contributed to the Innovation-Based Manufacturing of national economy such as unmanned reconnaissance aircraft, water purification technology, and mobile chemical laboratory, etc. The military forces in Eastern Europe are re-armed by the localization of self-produced munitions in their own defense industry, and then emphasize fostering their own defense industry. Thus, if they make a collaboration with other nations as a industrial cluster, it will gain a competitive edge on the defense industry. Research design, data, and methodology - The study was designed with the data of each national defense department. The research of the subject was reviewed before and after the transition. Thousands of workers have worked in defense industries before the transition, however, the defense industry and experts left after the transition. The Hungarian defense spending on GDP also dropped sharply from 1.72% in 2000 to 0.85% in 2013. But, due to the crisis in Ukraine and the crisis of Syrian refugees, the Viségrad Group (V4) member countries have also increased their interest in a defense and industries as well as the confidence in the EU and NATO. Results - On the whole, the joint of military training and purchase of defense materials were found in order to form the EU cooperative combat troops in CEE. There are the implementation of a joint manual plan for strengthening V4 security policy and the joint military exercises for V4 every year, and the others are electronic warfare and innovation of V4 national forces. Through such a performance analysis methodology, we found that the defense industry is developed through the national cluster cooperation among CEEs and spreading global distribution. Conclusions - Eastern Europe and Balkan countries have been looking forward to cooperating with the non-EU countries such as Korea and other defense industries. There are a lot of potential development into a new civilian cooperation defense industry for global-distribution. Thus, Korea should develop electronic commercial applications, not just as a weapon exporting region.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.19-24
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• 2024

In this paper, in order to realize lower cut-off frequency of the waveguide, the folded Ridge waveguide (FRWG) is suggested by alternating T-shape structure in the conventional folded waveguide with Y-shape structure. Suggested FRWG can be equivalent by the reverse Ridge waveguide. As the height of side of the FRWG is lower, the width of side is increased. Therefore, the cut-off frequency of the FRWG can be decreased more than half compared with conventional waveguide. The FRWG is designed with the length, height, and width of Y-shape structure of 40mm, 20mm, and 2mm, respectively. Designed FRWG has the cut-off frequency of the 1.996GHz. Also, the transition between the FRWG and SMA connector is designed. The transition is optimized by the capacitance of the signal line of the connector. Its result shows the VSWR under 2:1 in the band of 2.064 ~ 3.050 GHz. Suggested FRWG can be applied with miniaturization of various waveguide devices.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.701-705
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• 2002

This paper describes implementation of IPv6-IPv4 transition toolbox named as 6TALK(IPv6 TrAansLator of Krv6) and some scenarios using 6TALK which enables IPv6 island to connect other IPv6 island or IPv4 island seamlessly. 6TALK implements some transition mechanisms suggested in NGTrans Working Group of IETF. Those mechanisms are composed of basic mechanism, tunneling, and applied mechanism such as DSTM. 6TALK provides functions which enable IPv6 network at the edge of existing network to communicate with IPv4 network by using these transition mechanisms. As major transition mechanisms in 6TALK we adopt NAT-PT/SIIT and DSTM/DSTM options and as implementation environment we use Linux Kernel 2.4.18 and Netfilter framework. Software modules implemented in Linux kernel was ported to hardware box using Motorola MPC 8260 processor. The transition mechanisms used in 6TALK are the ones predicted to be used in initial transition step to IPv6.

• Vacuum Magazine
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• v.5 no.2
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• pp.10-17
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• 2018

Chalcogenide and oxide heterostructures have been studied as a next-generation electronic materials, due to their interesting electronic properties, such as direct bandgap semiconductor, ferroelectricity, ferromagnetism, superconductivity, charge-density waves, and metal-insulator transition, and their modification near heterointerfaces, so called, electronic reconstruction. An angle-resolved photoemission spectroscopy (ARPES) is a powerful technique to unveil such novel electronic phases in detail, especially combined with high quality thin film preparation methods, such as, molecular beam epitaxy and pulsed laser deposition. In this article, the recent ARPES results in chalcogenide and oxide thin films will be introduced.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.1
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• pp.1-7
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• 2021

ε-Ga2O3, a metastable phase of Ga2O3, has excellent compatibility with substrates having a hexagonal structure or a quasi-hexagonal structure, so that a film having a relatively lower surface roughness and defect density than β-Ga2O3 can be obtained easily. Accordingly, we attempted to fabricate a high-quality β-Ga2O3 film with a low surface roughness and defect density using the property of phase transition to β-Ga2O3 when ε-Ga2O3 is annealed at a high temperature. For this, the growth of high-quality ε-Ga2O3 films must be preceded. In this study, the optimal flow rate was investigated by analyzing the structural and morphological characteristics of the ε-Ga2O3 film according to the supplied precursor ratio. In addition, the annealing condition and the effect of β-Ga2O3 mixed in the ε-Ga2O3 film on the crystallinity of β-Ga2O3 after phase transition were also investigated.

• Proceedings of the Korean Magnestics Society Conference
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• 2011.12a
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• pp.95-95
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• 2011

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.148-148
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• 2007