• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.924-926
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• 1997

A high impedance fault(HIF) in a power system could be due to a downed conductor, and is a dangerous situation because the current may be too small to be detected by conventional means. In this paper, HIF(High impedance fault) and LIF(Low impedance fault) detection methods were reviewed. No single defection method can detect all electrical conditions resulting from downed conductor faults, because high impedance fault have arc phenomena, asymmetry and randomness. Neural network are well-suited for solving difficult signal processing and pattern recognition problem. This paper presents the application of artificial neural network(ANN) to detect the HIF and LIF. Test results show that the neural network was able to identify the high impedance fault by real-time operation. Furthermore, neural network was able to discriminate the HIF from the LIF.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.397-402
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• 2003

The FM demodulation method for a bulk homodyne laser interferometer is presented. The Doppler frequency that represents the surface velocity of a vibrating object is obtained by using the bulk homodyne laser interferometer, and converted to the voltage signal by using the proposed analogue FM demodulation circuit. The DC offsets of the interferent signals that are obtained from the bulk homodyne interferometer are eliminated by using a simple subtraction. The new method for compensation of the asymmetry of each channels is presented. The light power variation of the interferometer is normalized by using the Auto Gain Controller(AGC). The proposed FM demodulation algorithm is proved by the theoretical method, and validated by the experimental results. In experiments, the proposed FM demodulation algorithm is compared with the conventional demodulation methods.

• English Language & Literature Teaching
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• v.13 no.2
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• pp.177-200
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• 2007

The language socialization approach states that novices are socialized into cultural norms through participating in routine, repeated interactional acts and sequences (e.g., Ochs & Schieffelin, 1984; Ochs, 1988; Schieffelin & Ochs, 1986a; 1986b; Watson-Gegeo & Gegeo, 1986). One of the cultural norms or dominant epistemological orientations in American culture is the tendency to avoid the overt display of power asymmetry in novice-expert relationship (Ochs & Schieffelin, 1984). This study examines how this cultural preference is reflected and encoded in ESL teachers' use of routine discourse patterns in corrective sequences. Eight hours of ESL classes taught by three Caucasian teachers born and educated in the U.S. were analyzed for the study. The analysis showed that the cultural tendency in question is keyed and indexed in the teacher's routine corrective discourse patterns in the form of various questioning, elicitation, and mitigation practices. Findings support that teachers' routine classroom discourse practices represent their cultural ideologies and transfer these cultural predispositions to second language learners and that they possibly socialize the learners into the target language-oriented beliefs.

• Current Optics and Photonics
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• v.2 no.3
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• pp.215-220
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• 2018

A novel porous-core hexagonal lattice photonic crystal fiber (PCF) is designed and analyzed for efficient terahertz (THz) wave propagation. The finite element method based Comsol v4.2 software is used for numerical analysis of the proposed fiber. A perfectly matched layer boundary condition is used to characterize the guiding properties. Rectangular air-holes are used inside the core to introduce asymmetry for attaining high birefringence. By intentionally rotating the rectangular air holes of porous core structure, an ultrahigh birefringence of 0.045 and low effective material loss of $0.086cm^{-1}$ can be obtained at the operating frequency of 0.85 THz. Moreover, single-mode properties, power fraction in air core and confinement loss of the proposed PCF are also analyzed. This is expected to be useful for wideband imaging and telecom applications.

• Journal of Drive and Control
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• v.13 no.1
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• pp.34-42
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• 2016

This study studied how the clearance, overlap and mismatch errors of spool-sleeve affect the static pressure characteristics of a servo valve. A computer simulation model was established as a direct acting servo valve and a series of simulations was conducted for various values of clearance, overlap and mismatch errors. Pressure gain decreased as the clearance increased. The overlap also affects the pressure gain and was similar to the effect of clearance. Asymmetry of the pressure plot got worse and worse as the mismatch error increased.

• Journal of Contemporary Eastern Asia
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• v.20 no.2
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• pp.197-209
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• 2021

This article deals with the asymmetrical relations between Australia and China and explores their interdependence, tensions, and societal outlooks. Both countries are dependent on one another for trade to different degrees but attempt to diversify their supply chains. While there is no united position on China in Australia, there has been a bipartisan support for the counter-interference legislation there. The newly established security pact of the United States (US), the United Kingdom (UK) and Australia - 'AUKUS' - has brought a new dimension into these tensions and will most likely lead to an arms race. The author explores how a so-called middle power such as Australia balances the related economic and strategic interests and priorities. Although Australia has been vulnerable in its asymmetric relationship with China, it has shown that it is not a passive and helpless actor when facing an economic coercion. The interdependence has become a moderating factor in this strategic stand-off. Additionally, Australia demonstrates its tendency to reinforce its traditional reliance on its previous more powerful allies, the UK and the US.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.357-367
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• 2021

In general, common cause failures (CCFs) have been modeled with the assumption that components within the same group are symmetric. This assumption reduces the number of parameters required for the CCF probability estimation and allows us to use a parametric model, such as the alpha factor model. Although there are various asymmetric conditions in nuclear power plants (NPPs) to be addressed, the traditional CCF models are limited to symmetric conditions. Therefore, this paper proposes the copulabased CCF model to deal with asymmetric as well as symmetric CCFs. Once a joint distribution between the components is constructed using copulas, the proposed model is able to provide the probability of common cause basic events (CCBEs) by formulating a system of equations without symmetry assumptions. In addition, Bayesian inferences for the parameters of the marginal and copula distributions are introduced and Markov Chain Monte Carlo (MCMC) algorithms are employed to sample from the posterior distribution. Three example cases using simulated data, including asymmetry conditions in total failure probabilities and/or dependencies, are illustrated. Consequently, the copula-based CCF model provides appropriate estimates of CCFs for asymmetric conditions. This paper also discusses the limitations and notes on the proposed method.

• Journal of Distribution Science
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• v.15 no.11
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• pp.73-82
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• 2017

Purpose - This paper aims to investigate a profit maximizing incentive of foreign traders in distributing the KOSPI 200 Futures. Such an incentive may induce unsophisticated retail traders to suffer loss from speculative trading. Since Korean government increased the entry barriers of the market to protect unsophisticated traders, the market size has been decreasing while the proportion of the contract held by foreign traders has been increasing. These on going changes make the market imperfectly competitive, where a profit maximization incentives of foreign traders are expected to grow. In this paper, we attempt to find any evidence of such behavior, thereby providing implications regarding market policy and market efficiency. Research design, data, and methodology - According to Kyle(1985), an informed trader exploits his/her monopoly power optimally in a dynamic context so that he/she makes positive profit, where he/she could conceal his/her trading utilizing noise trading as camouflage. We apply the KOSPI 200 Futures market to the Kyle's model: foreign traders who take into account the effect of his/her trading to maximize expected profits as an informed trader, retail investors as noise traders, and financial institutions as market makers. To find any evidence of monopolistic behavior, we test the variants of trading volume and price data of the KOSPI 200 Futures over the period of 2009 and 2017. Results - First, we find that the price of the KOSPI 200 Futures are more volatile than the price of underlying asset. Second, we find that monopolistic foreign trader's trading order flows are consistent with exploiting his/her monopoly power to maximize profit. Finally, we find that retail investors' trading order flows are inversely consistent with maximizing profit, that is, uninformed retail investors suffer loss continuously in speculative trading against informed traders. Conclusions - Our results show that the quantity of strategic order flows may have a large effect on the price, therefore, resulting the market inefficiency. The results also imply that, in implementing regulations, the depth of the market must be considered to maintain market liquidity, and suggesting interesting research topics regarding the market structure.

• Journal of Distribution Research
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• v.13 no.2
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• pp.1-27
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• 2008

In a power-asymmetry relationship like franchise system, a high dependent franchisee must often rely on its powerful partner. Therefore, in order to build up 'win-win' systems, therefore channel members should increase trust and commitment each other to enhance the relationship quality to sustain long-term cooperative relationships. First of all, to increase the relationship quality in franchise system, franchisor should increase franchisee's perception of the powerful franchisor's justice. The point of this research, I established basic hypotheses and comparative hypotheses to examine franchisor's behavior what franchisee expected which influences on franchisee's attitude and behavior in power - asymmetry relationship in franchise system. For the purpose of the empirical testing, managers of franchisee in the food service industry of Korea had been selected and analyzed, and major findings in this study as follow: First, the relational norm between franchisor and franchisee increased both distributive justice and procedural justice, especially relational norm had more effect on procedural justice than distributive justice. Second, distributive justice increased both economic commitment and social commitment while procedural justice just increased social commitment only but economic commitment. So, on the relational commitment, distributive justice was more important element than procedural justice. On the other hand, procedural justice had indirect effect on economic commitment through distributive and social commitment.

• Sleep Medicine and Psychophysiology
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• v.27 no.2
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• pp.67-76
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• 2020

Objectives: Brain maturation involves brain lateralization and asymmetry to achieve efficient information processing and cognitive controls. This study elucidates normal brain maturation change during the gap between ages 6-9 and age 14-17 using resting EEG. Methods: An EEG dataset was acquired from open source MIPDB (Multimodal Resource for Studying Information Processing in the Developing Brain). Ages 6-9 (n = 24) and ages 14-17 (n = 26) were selected for analysis, and subjects with psychiatric illness or EEG with severe noise were excluded. Finally, ages 6-9 (n = 14) and ages 14-17 (n = 11) were subjected to EEG analysis using EEGlab. A 120-sec length of resting EEG when eyes were closed was secured for analysis. Brain topography was compartmentalized into nine regions, best fitted with brain anatomical structure. Results: Absolute power of the delta band and theta band in ages 6-9 was greater than that of ages 14-17 in the whole brain, and, also is relative power of delta band in frontal compartment, which is same line with previous studies. The relative power of the beta band of ages 14-17 was greater than that of ages 6-9 in the whole brain. In asymmetry evaluation, relative power of the theta band in ages 14-17 showed greater power in the left than right frontal compartment; the opposite finding was noted in the parietal compartment. For the alpha band, a strong relative power distribution in the left parietal compartment was observed in ages 14-17. Absolute and relative power of the alpha band is distributed with hemispheric left lateralization in ages 14-17. Conclusion: During the gap period between ages 6-9 and ages 14-17, brain work becomes more complicated and sophisticated, and alpha band and beta band plays important roles in brain maturation in typically developing children.