• Journal of Information Technology and Architecture
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• v.10 no.2
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• pp.223-236
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• 2013

Related to the situation on the Korean Peninsula, by North Korea's threat of war the tension escalates and serious crisis continues. The purpose of this study is to evaluate the subjective perception which the residents of South Korea feel about North Korea's threat of war through a Q methodological analysis framework. In the result of the study, for the North Korea's threat of war the South Korean's recognition type is analyzed into four type such as 'non-reactive', 'fearreactive', 'psychological anxiety' and 'cynical ignorance type'. First, the No. 1 type 'non-reactive' does not empathize with North Korea's threat of war itself, and second type 'fear-reactive' have uneasy feeling like that 'What would happen as things go' and feel a sense of crisis about the North Korea's threat of war. The third type 'psychological anxiety' is type which feels that due to North Korea's threat of war inter-Korean relations is in the crisis. Finally the fourth type 'cynical ignorance' think that North Korea's threat of war is bluffing and also North Korea is like a shepherd boy. The reason to apply Q-methodology in this study is to make it possible to a more in-depth approach to subjective perception and threat of psychological meaning for the threatening message of study participants.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2410-2414
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• 2014

A kinetic study is reported on nucleophilic substitution reactions of Y-substituted-phenyl picolinates (7a-7h) with a series of cyclic secondary amines in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. Comparison of the kinetic results with those reported previously for the corresponding reactions of Y-substituted-phenyl benzoates (1a-1f) reveals that 7a-7h are significantly more reactive than 1a-1f. The Br${\o}$nsted-type plot for the aminolysis of 4-nitrophenyl picolinate (7a) is linear with ${\beta}_{nuc}=0.78$, which is typical for reactions proceeding through a stepwise mechanism with expulsion of the leaving group being the rate-determining step. The Br${\o}$nsted-type plots for the piperidinolysis of 7a-7h and 1a-1f are also linear with ${\beta}_{lg}=-1.04$ and -1.39, respectively, indicating that the more reactive 7a-7h are less selective than the less reactive 1a-1f to the leaving-group basicity. One might suggest that the enhanced reactivity of 7a-7h is due to the inductive effect exerted by the electronegative N atom in the picolinyl moiety, while the decreased selectivity of the more reactive substrates is in accord with the reactivity-selectivity principle. However, the nature of intermediate (e.g., a stabilized cyclic intermediate through the intramolecular H-bonding interaction for the reactions of 7a-7h, which is structurally not possible for the reactions of 1a-1f) is also responsible for the enhanced reactivity with a decreased selectivity.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.236-237
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• 2006

A microgrid is a new type of power system which is formed by the interconnection of small generator to distribution systems. Microgrids are able to supply electric power to their loads independently, which is called with islanding operation, even if they're separated from the power system. As a result, microgrids must be equipped with specific islanding detection schemes for the islanding operation of microgrids. This paper studies an islanding detection method considering reactive power. The proposed method is dealing with the reactive power of the cable which connects between a microgrid and a power system. To show the validity of the proposed method, many islanding operation cases are tested by varying the load conditions of microgrids.

• Journal of Power Electronics
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• v.18 no.2
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• pp.604-614
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• 2018

This paper proposes a synchronous switching technique for a Vienna rectifier that uses carrier-based pulse width modulation (CB-PWM). A three-phase Vienna rectifier, similar to a three-level T-type converter with three back-to-back switches, is used as a PWM rectifier. Conventional CB-PWM requires six independent gate signals to operate back-to-back switches. When internal switches are operated synchronously, only three independent gate signals are required, which simplifies the construction of gate driver circuits. However, with this method, total harmonic distortion of the input current is higher than that with conventional CB-PWM switching. A reactive current injection technique is proposed to improve current distortion. The performance of the proposed synchronous switching method and the effectiveness of the reactive current injection technique are verified using simulations and experiments performed with a set of Vienna rectifiers rated at 5 kW.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.185-190
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• 2003

고유전물질인 $HfO_2$ 극박막에 사용될 TaN metal 전극에 대한 특성에 대한 연구를 하였다. 고유전물질인 $HfO_2$는 4" p-type wafer를 SCI cleaning후 ALD(atomic layer deposition)을 통해 $50\AA$를 증착하였다. Ff source는 TEMAH를 이용하였으며 Oxygen source는 $H_2O$를 이용하였다. 이렇게 증착한 $HfO_2$ 극박막에 Ta target을 이용하여 질소 가스를 Ar가스에 첨가하여 reactive sputtering을 통해서 TaN 전극을 증착하였다. TaN 박막의 증착두께는 a--step과 TEM을 통해서 확인하였으며 면저항은 four point probe를 이용하여 측정하였다. 이렇게 증착된 $HfO_2/TaN$구조에 대한 전기적 특성을 측정하였다.

• Textile Coloration and Finishing
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• v.19 no.2
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• pp.7-13
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• 2007

Photopolymerization of 2-hydroxyethyl methacrylate(HEMA), in the presence of ethyleneglycol dimethacrylate(EGDMA) and 1-Hydroxycyclohexyl phenyl ketone as crosslinker and photoinitiator, respectively, produced crosslinked poly-HEMA hydrogels. The hydrogels were colored by the exhaustion of vinylsul-phone-type reactive dyes. Good colorfastness to laundering was achieved when colored with C.I. Reactive Black 5. We investigated that the effect of coloration on the hydrophilicity and swelling properties of the films. More hydrophilic gel-surfaces were generated with in increase in coloration and crosslinking. Higher surface energy was observed with higher crosslinking level. The more rapid and higher water swellability of poly-HEMA gels after coloration may be resulted from a more opened gel structure by the easier hydration of the hydrophilic sulphonic acid groups of the reacted dyes in water.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.12
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• pp.715-726
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• 1999

This paper estimates the capacity of shunt type active power filters(APF) for harmonic/reactive power compensation with a thyristor converter load. The base capacity requirement of APF is defined for idealized converter load current waveform and the effect of commutation overlap on the APF capacity is examined. The APF capacity required for reactive power compensation in addition to the harmonic elimination is estimated to give maximum achievable power factor for various operating condition of the partially-loaded thyristor converter. The method of current limit of APF is introduced, and it is shown that the APF capacity can be considerably reduced by deliberately limiting the peak current while maintaining the filtering performance to meet the level std 519 regulation.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.202-204
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• 1993

Appropriate control of real and reactive power flowing in and out from system can lead to considerable benefits : network stabilization, load leveling, voltage regulation etc. This paper presents how to control real and reactive power flow between an flywheel energy storage system and a power three phase network. The system compensating real and reactive power consists of control system and cycloconverter operating in the four quadrant modes.

• Journal of Life Science
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• v.25 no.2
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• pp.231-236
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• 2015

Angiotensin II (AngII) is an essential hormone that affects vascular physiology. For example, stimulation of vascular smooth muscle cells (VSMCs) rapidly induces vasoconstriction and results in the up-regulation of blood pressure. Chronic stimulation of VSMCs with AngII also results in hypertrophy. In this study, we confirmed an involvement of phosphatidylinositol 3-kinase (PI3K)-dependent calcium mobilization in AngII-induced generation of reactive oxygen species (ROS). Stimulation of rat aortic smooth muscle cells (RASMCs) with AngII significantly induced the generation of ROS in a dose- and time-dependent manner. AngII-induced generation of ROS was completely abolished by pharmacological inhibition of PI3K (with LY294002), but inhibition of the ERK signaling pathway had no effect. AngII-induced calcium mobilization was completely blocked by inhibition of PI3K, whereas inhibition of the ERK signaling pathway by PD98059 was ineffective. Depletion of extracellular calcium or inhibition of the L-type calcium channel by nifedipine completely blocked AngII-induced calcium mobilization. Depletion of extracellular calcium by EGTA and incubation of RASMCs with calcium-free medium both significantly blocked AngII-induced ROS generation. Inhibition of the L-type calcium channel also significantly blocked AngII-induced ROS generation. These results suggest that AngII-induced ROS generation is regulated by calcium mobilization, which, in turn, is modulated by a PI3K/L-type calcium channel signaling pathway.

• Korean Journal of Childcare and Education
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• v.15 no.6
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• pp.77-98
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• 2019

Objective: The purpose of this study was to examine the effect of adolescents' callousness on reactive and proactive aggression through moral disengagement. Methods: The participants were 315 freshmen and sophomore high school student in Korea. The data were analyzed with Structural Equation Modeling(SEM). Results: First, adolescents' callousness did not show a significant influence on reactive aggression directly or indirectly through moral disengagement. Second, adolescents' callousness had a significant influence on proactive aggression directly and indirectly through moral disengagement. That is, adolescents' high level of callousness not only predicts a higher level of proactive aggression directly, but also influences moral disengagement which may result in a high level of proactive aggression. In addition, the gender difference in this model was confirmed. Conclusion/Implications: The results of this study indicated that adolescents' callousness could have different influences on aggression through moral disengagement by the types of aggression and gender. The results suggest that it is necessary to approach the emotional and cognitive process of adolescent aggression differently, depending on the type of aggression and gender.